Molecular pump and semiconductor device

Abstract

The invention relates to the field of vacuumizing, and discloses a molecular pump and semiconductor equipment. The molecular pump comprises a shell, a motor and a rotating body, the motor comprises a motor shell and a rotating shaft, the rotating body comprises a base part which is installed at the output end of the rotating shaft and surrounds the motor shell, and a sleeving gap with an opening is formed between the base part and the motor shell; the surface, facing the sleeving gap, of at least one of the motor shell and the base part is provided with one or more air guide grooves extending in a spiral mode, the surface, facing the sleeving gap, of at least one of the motor shell and the base part is provided with one or more air guide grooves extending in a spiral mode, and each air guide groove comprises a starting end and a stopping end which are opposite in the extending direction. The starting end is the end, close to the output end, of the air guide groove, the terminating end is the end, away from the output end, of the air guide groove, and the air guide groove extends in the first direction and the second direction simultaneously from the starting end to the terminating end. The molecular pump can solve the problems that the pressure on the inlet side of the molecular pump is increased and the vacuum degree is reduced possibly due to introduction of protective gas.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vacuum pumping, and more particularly, to a molecular pump and a semiconductor device. BACKGROUND

[0002] In the application of molecular pumps, it is often encountered that the pumped gas contains gas components that may harm the components inside the pump, such as the pumped gas containing reactive gases such as hydrogen, high-temperature oxygen, or the pumped gas containing corrosive gases or easily condensable gases. The entry of harmful pumped gas into movable components such as motors can seriously affect their normal operation. For example, hydrogen or corrosive gas may cause the bearings in the motor to fail due to hydrogenation reaction or chemical corrosion; easily condensable gas may form deposits in the pump, narrowing the gap between movable and stationary components, causing unexpected friction, thereby reducing the operating efficiency, reliability and service life of the molecular pump.

[0003] To address this challenge, gas purging technology is widely used to protect the internal components of the molecular pump. The core principle of the gas purging technology is to introduce a protective gas into the interior of the molecular pump, and through a specially designed channel, the protective gas can pass through the motor stator, the motor shaft, and the gap between the motor and the rotating body of the molecular pump, and finally flow to the channel through which the pumped gas flows, and is discharged from the outlet of the molecular pump to the outside of the pump. However, the injection of the protective gas will cause the pressure on the inlet side of the molecular pump to rise, thereby reducing the vacuum degree, reducing the performance of the molecular pump, and limiting its application effect in fields with high requirements such as high vacuum and ultra-high vacuum. SUMMARY

[0004] The present application provides a molecular pump and a semiconductor device to improve the current situation that the molecular pump using gas purging technology reduces performance in the related art.

[0005] In a first aspect, the embodiments of the present application provide a kind of molecular pump, the molecular pump includes shell, motor and rotating body, shell is equipped with cavity;Motor includes motor shell and rotating shaft, motor shell is installed on shell, and the output end of rotating shaft is located in cavity;And rotating body, including base and moving blade stage, base is installed on output end, and it surrounds motor shell, and there is a sleeving gap between base and motor shell, the side of sleeving gap has an opening away from output end, and moving blade stage is fixed to base;At least one of motor shell and base is provided with one or more gas guide grooves extending spirally on the surface towards the sleeving gap, each gas guide groove includes opposite start end and end along the extension direction, the start end is one end of the gas guide groove close to the output end, and the end is one end of the gas guide groove away from the output end, from the start end to the end, the first direction is the direction of the output end of the rotating shaft pointing to the other end of the rotating shaft, and the second direction is opposite to the reference direction, wherein the reference direction is the relative rotation direction of one of the motor shell and the base relative to the other one of the motor shell and the base.

[0006] In the embodiments, at least one of the motor shell and the base is provided with one or more gas guide grooves extending spirally on the surface towards the sleeving gap, each gas guide groove includes opposite start end and end along the extension direction;Wherein, the start end is one end of the gas guide groove close to the output end, and the end is one end of the gas guide groove away from the output end, from the start end to the end, the gas guide groove extends along the first direction and the second direction at the same time;Wherein, the first direction is the direction of the output end of the rotating shaft pointing to the other end of the rotating shaft, and the second direction is opposite to the reference direction, which is the relative rotation direction of one of the motor shell and the base relative to the other one of the motor shell and the base. When the rotating body rotates, the inner wall of the rotating body drives the gas molecules to move tangentially, so that the gas molecules obtain a tangential velocity, and then the gas molecules move relative to the motor shell and the base. Since the reference direction is the relative rotation direction of one of the motor shell and the base relative to the other one of the motor shell and the base, the reference direction is also the rotation direction of the structure provided with the gas guide relative to the gas molecules;In other words, the rotation direction of the gas molecules relative to the structure provided with the gas guide is the second direction opposite to the reference direction. Therefore, when the extension direction of the gas guide groove from the start end to the end is one side along the first direction and the other side along the second direction, the gas molecules will flow along the gas guide groove, and finally be discharged from the end of the gas guide groove. This process forms an active and one-way gas transport effect, which blocks the reverse penetration of harmful gases such as corrosive and reactive gases to the deep part of the gap, thereby reducing the risk of performance degradation and damage of internal core components such as rotating shaft and motor caused by chemical corrosion, physical deposition or abnormal reaction. Since the above protection mechanism is realized by the reverse spiral structure of the gas guide groove, it does not need to rely on external injection of protective gas, so it can improve the problem of pressure rise and vacuum degree drop at the inlet side of the molecular pump caused by the introduction of protective gas.

[0007] In a possible implementation, the outer surface of the motor housing is provided with one or more air guide grooves, and the second direction is the same as the rotation direction of the rotating body. In the embodiment of the application, the air guide grooves are arranged on the motor housing. Since the motor housing is a stationary component during operation, the precision requirement of the machining process is relatively low, and therefore the machining is easy to implement and the manufacturing cost is low.

[0008] In a possible implementation, the one or more air guide grooves are formed by concave processing on the outer surface of the motor housing. In the embodiment of the application, the air guide grooves are formed by directly concave processing on the surface of the motor housing. When the sleeve gap is small, it is not convenient to process an outwardly convex structure on the surface of the motor housing to form the air guide grooves, because this requires high dimensional machining precision to reduce the risk of interference when the motor housing is assembled with the rotating body. In comparison, the air guide grooves formed by concave processing on the surface of the motor housing can overcome the above-mentioned deficiencies. This structure can meet sufficient exhaust performance in the case of a small sleeve gap, and has lower processing requirements and is easy to implement in industrialization.

[0009] In a possible implementation, the molecular pump further comprises at least two flow guide vanes, the flow guide vanes are arranged on the outer surface of the motor housing and extend in a spiral shape, and one of the one or more air guide grooves is formed between two adjacent flow guide vanes. In the embodiment of the application, the flow guide vanes protrude from the outer surface of the motor housing. When the sleeve gap is large, the flow guide vanes arranged on the outer surface of the motor housing and extending in a spiral shape in the sleeve gap correspond to a stator vane stage structure, which can guide the axial flow of gas molecules in a larger sleeve gap and has stronger exhaust performance.

[0010] In a possible implementation, the motor housing is provided with a plurality of air guide grooves, and the plurality of air guide grooves arranged on the motor housing are arranged at intervals in the second direction.

[0011] In the embodiment of the application, the plurality of air guide grooves are arranged at intervals in the second direction, forming a plurality of independent gas exhaust channels, so that the gas can be efficiently exhausted through multiple paths when the rotating body rotates, significantly improving the exhaust efficiency of the gas and reducing the residence time of the gas in the sleeve gap.

[0012] In a possible implementation, the inner surface of the base is provided with one or more air guide grooves, and the second direction is opposite to the rotation direction of the rotating body.

[0013] In this embodiment, the gas guide groove is disposed at the base. Since the gas molecules in the sleeve gap rotate relative to the motor housing under the drive of the rotating body, the rate at which the gas in the sleeve gap is discharged from the sleeve gap through the gas guide groove is affected by the relative velocity between the rotating body and the gas in the sleeve gap. The rotating body is a rotating component in the molecular pump. When the molecular pump starts, the relative velocity between the rotating body and the gas in the sleeve gap is greater than the relative velocity between the gas in the sleeve gap and the motor housing. That is, when the molecular pump starts, the method of disposing of the gas guide groove at the base of the rotating body in this embodiment can achieve higher exhaust performance.

[0014] In one possible implementation, the air guide groove provided on the base is formed by an indentation on the inner surface of the base.

[0015] In this embodiment, the air guide groove is formed by directly machining the inner surface of the base inward. When the sleeve gap is small, it is not convenient to machine the inner surface of the base into an outward convex structure to form the air guide groove, because this requires controlling high dimensional accuracy to reduce the risk of interference when the base is assembled with the motor housing. In contrast, forming the air guide groove by machining the inner surface of the base inward can overcome the above-mentioned shortcomings. This setting can meet sufficient exhaust performance in the case of small sleeve gap and has lower processing requirements, making it easier to achieve industrialization.

[0016] In one possible implementation, the molecular pump further includes at least two guide vanes disposed on the inner surface of the base and extending in a spiral shape, with one of one or more gas guide slots formed between adjacent guide vanes.

[0017] In this embodiment, the guide vane protrudes from the inner surface of the base; when the sleeve gap is large, the guide vane is set on the outer surface of the motor housing and the structure that extends spirally in the sleeve gap is equivalent to the moving blade stage structure, which can guide gas molecules to flow axially in the larger sleeve gap and has stronger exhaust performance.

[0018] In one possible implementation, the base is provided with a plurality of air guide grooves, which are arranged at intervals along a second direction.

[0019] In this embodiment, multiple air guide grooves are arranged at intervals along the second direction to form multiple independent gas discharge channels, which enables the gas to be efficiently discharged through multiple paths when the rotating body rotates, significantly improving the gas discharge efficiency and reducing the gas residence time in the sleeve gap.

[0020] In one possible implementation, one or more air guide grooves are provided on the outer surface of the motor housing and the inner surface of the base, and at least one of the outer surface of the motor housing and the inner surface of the base is recessed to form one or more air guide grooves; along the axial direction of the rotating shaft, the extension range of one or more air guide grooves provided on the motor housing at least partially overlaps with the extension range of one or more air guide grooves on the base.

[0021] In this embodiment, the air guide groove provided on the motor housing and the air guide groove provided on the base overlap in the axial direction of the rotating shaft. Thus, the air guide groove of the motor housing and the air guide groove of the base constitute a continuous exhaust structure, which can improve the exhaust efficiency. At the same time, one of the motor housing and the base can form one or more air guide grooves through inward concavity, and the other can form an air guide groove through inward concavity or outward convex guide vanes, etc. Therefore, even if the air guide groove of the motor housing and the air guide groove of the base overlap in the axial direction of the rotating shaft, the two will not interfere with each other.

[0022] In one possible implementation, the molecular pump further includes a plurality of guide vanes; at least two first guide vanes are disposed on the outer surface of the motor housing and extend in a spiral shape, and one of one or more air guide grooves is formed between two adjacent first guide vanes, wherein the first guide vanes are guide vanes disposed on the motor housing; at least two second guide vanes are disposed on the inner surface of the base and extend in a spiral shape, and one of one or more air guide grooves is formed between two adjacent second guide vanes, wherein the second guide vanes are guide vanes disposed on the base; along the axial direction of the rotating shaft, the extension range of the first guide vanes and the extension range of the second guide vanes are staggered.

[0023] In this embodiment, the motor housing and the base are respectively formed by first and second guide vanes to create air guide channels. During the rotation of the rotating body, the first and second guide vanes correspond to the stationary and moving blade stages, respectively. This arrangement allows all the air guide channels in the molecular pump to work together to achieve a stronger exhaust effect. Furthermore, the air guide channels in the motor housing and the base are offset along the axis of rotation. Therefore, the rotating body will not interfere with the first guide vane of the motor housing during rotation. Thus, this embodiment can achieve higher exhaust performance in the air guide channels of the molecular pump under the condition that the rotating body rotates safely.

[0024] In one possible implementation, it further includes at least one stationary blade stage, which is located in the cavity and fixed to the housing, and the moving blade stage and the stationary blade stage are alternately distributed along the axial direction of the rotating shaft.

[0025] In this embodiment, the moving blade stage and the stationary blade stage are alternately distributed along the axial direction, forming a multi-stage pumping mechanism, which can significantly improve the overall pumping efficiency of the molecular pump and reduce the pumping time.

[0026] Secondly, embodiments of this application also provide a semiconductor device, which includes a machine base and the aforementioned molecular pump. The machine base has an inner cavity, the molecular pump is mounted on the machine base, and the inlet of the molecular pump communicates with the inner cavity.

[0027] In this embodiment of the application, the semiconductor device includes the aforementioned molecular pump, which can improve the shortcomings of the related technology that require a purge gas channel for the molecular pump, thereby causing an increase in the inlet pressure and a decrease in the vacuum level of the molecular pump. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 A cross-sectional view of the molecular pump provided in an embodiment of this application;

[0030] Figure 2 This is a cross-sectional view of a first embodiment of the air guide groove provided in this application.

[0031] Figure 3 for Figure 2 Partial three-dimensional schematic diagram of the motor housing;

[0032] Figure 4 This is a cross-sectional view of a second embodiment of the air guide groove provided in this application.

[0033] Figure 5 for Figure 4 Schematic diagram of the structure of the motor housing;

[0034] Figure 6 This is a cross-sectional view of a third embodiment of the air guide groove provided in this application.

[0035] Figure 7 for Figure 6 A three-dimensional schematic diagram of a solid of revolution;

[0036] Figure 8 This is a cross-sectional view of a fourth embodiment of the air guide groove provided in this application.

[0037] Figure 9 for Figure 8 A three-dimensional schematic diagram of a solid of revolution;

[0038] Figure 10 This is a cross-sectional view of the fifth embodiment of the air guide groove provided in this application.

[0039] Figure 11 This is a cross-sectional view of the sixth embodiment of the air guide groove provided in this application.

[0040] Figure 12 This is a schematic diagram of a semiconductor device provided in an embodiment of this application.

[0041] Explanation of reference numerals in the attached figures:

[0042] 100-Molecular pump;

[0043] 1-Outer shell, 11-Cylinder, 12-End, 13-Stationary blade stage, 101-Cavity, 102-Outlet;

[0044] 2-Motor, 21-Motor housing, 22-Shaft, 221-Output terminal;

[0045] 3-Rotating body, 31-Base, 32-Moving blade stage;

[0046] 4-Setting gap, 41-Opening;

[0047] 5-Air guide groove;

[0048] 6-Flow guide vane;

[0049] 7-Holwick traction pump stage;

[0050] 200 - Semiconductor equipment; 210 - Machines. Detailed Implementation

[0051] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0052] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0053] Please see Figure 1 , Figure 1This is a cross-sectional view of a molecular pump 100 provided in an embodiment of this application. The molecular pump 100 includes a housing 1, a motor 2, and a rotating body 3. The housing 1 has a cavity 101. The motor 2 includes a motor housing 21 and a rotating shaft 22. The motor housing 21 is mounted on the housing 1, and the output end 221 of the rotating shaft 22 is located in the cavity 101. The rotating body 3 includes a base 31 and a moving blade stage 32. The base 31 is mounted on the output end 221 of the rotating shaft 22 and surrounds the motor housing 21. A fitting gap 4 is provided between the base 31 and the motor housing 21, and the fitting gap 4 has an opening 41 on the side away from the output end 221. The moving blade stage 32 is fixed to the base 31. Next, the above structure will be described in detail with reference to the accompanying drawings.

[0054] The outer casing 1 is a cylindrical structure sealed at one end. Specifically, the outer casing 1 includes a cylindrical body 11 and an end 12. The cylindrical body 11 is a hollow cylindrical structure; the end 12 is fixed to one end of the cylindrical body 11 and seals that end. The end 12 and the cylindrical body 11 together form the cavity 101 described above. The end of the outer casing 1 facing away from the end 12 is open for connecting the device to be evacuated and for allowing gas to enter the molecular pump 100. The outer casing 1 protects the internal components from the influence of the external environment, such as dust and humidity, and isolates the vacuum environment inside the pump from the external environment. It also provides a mounting position for the motor 2 and the rotating body 3, providing a favorable foundation for the reliable operation of the motor 2 and the rotating body 3.

[0055] The motor 2 is located in the cavity 101 and serves as the power source for the molecular pump 100. The motor 2 includes a motor housing 21 and a rotating shaft 22. The motor housing 21 is a cylindrical shell fixed to the end 12. The motor housing 21 can be fixed to the end 12 by mechanical means such as threaded connections or snap-fits, or it can be integrally formed with the end 12. In this embodiment, the motor housing 21 adopts a hollow, stepped cylindrical structure. Specifically, the motor housing 21 includes a small-diameter end and a large-diameter end coaxially arranged, smoothly connected by a tapered connecting section; the small-diameter end is closer to the output end of the rotating shaft 22, and the large-diameter end is farther from the output end of the rotating shaft 22. The main purpose of designing the motor housing 21 as a stepped cylindrical structure is to provide radial space for the moving blade stage 32 of the rotating body 3. Setting the small-diameter end of the motor housing 21 at the position corresponding to the moving blade stage 32 can prevent the diameter of the motor housing 21 from being too large at this position and compressing the diameter of the moving blade stage 32. The large-diameter end is set at the end far from the output end of the rotating shaft 22, and its position does not correspond to the moving blade stage 32, which is beneficial to the overall structural strength of the motor housing 21.

[0056] The rotating shaft 22 is the output component of the motor 2. One end of the rotating shaft 22 is located inside the motor housing 21, and the other end extends out of the motor housing 21 to form an output end 221, which is located in the cavity 101. The rotating body 3 is disposed in the cavity 101 and is the actuator for the molecular pump to achieve vacuuming. The rotating body 3 includes the base 31 and the moving blade stage 32. The base 31 is mounted on the output end 221 so that the rotating body 3 can rotate with the rotating shaft 22. The base 31 has a cylindrical structure and surrounds the motor housing 21; there is a sleeve gap 4 between the base 31 and the motor housing 21 to avoid direct contact and interference. The sleeve gap 4 has an opening 41 on the side away from the output end 221. The moving blade stage 32 is fixed to the base 31 and includes multiple moving blades ( Figure 7 (Seen in a three-dimensional view), the multiple moving blades are arranged around the base 31. The rotating body 3 may include multiple moving blade stages 32, which are arranged at intervals along the axial direction of the rotating shaft 22. When the motor 2 is energized, the motor 2 drives the rotating body 3 to rotate, and the moving blade stages 32 rotate at high speed around the axis of the rotating shaft 22, thereby conveying the gas on the side of the housing 1 away from the end 12 along the axial direction of the rotating shaft 22 into the cavity 101 to evacuate the device installed at the end of the housing 1 away from the end 12; the housing 1 has an outlet 102 at the end near the end 12 for outputting the gas conveyed by the moving blade stages 32. It should be noted that when the molecular pump needs to achieve vacuum, the rotation direction of the rotating shaft 22 and the moving blade stages 32 should be unidirectional. The following is based on Figure 1 The orientation of the molecular pump shown is illustrated using the clockwise rotation direction of the shaft 22 and the moving blade stage 32 as an example.

[0057] In this embodiment, the base 31 also has a three-section structure, comprising a small-diameter section, a tapered connecting section, and a large-diameter section connected in sequence. The small-diameter section is mounted on the output end 221 and houses the aforementioned moving blade stage 32. Due to its smaller diameter, the small-diameter section provides ample extension space for the moving blade stage 32. The large-diameter section, since it does not require the moving blade stage 32, can have a larger diameter to fit the large-diameter end of the motor housing 21. This configuration allows for a fitting gap between the motor housing 21 and the base 31, provided the motor housing 21 has sufficient strength, without creating an excessively large gap. Furthermore, an additional traction pump stage can be installed on the large-diameter section to enhance the vacuum pumping performance of the molecular pump 100.

[0058] Corresponding to the moving vane stage 32, the molecular pump also includes at least one stationary vane stage 13, with the moving vane stage 32 and stationary vane stage 13 alternately distributed along the axial direction of the rotating shaft 22. Specifically, the stationary vane stage 13 is located in the aforementioned cavity 101 and fixed to the outer casing 1, and includes multiple stationary vanes arranged around the rotating shaft 22. The alternating distribution of the stationary vane stage 13 and the moving vane stage 32 along the axial direction of the rotating shaft 22 forms a multi-stage pumping mechanism; the moving vane stage 32 generates centrifugal force through high-speed rotation, transporting gas from the molecular pump inlet to the aforementioned outlet direction, while the stationary vane stage 13 further reduces the temperature and pressure of the gas through diffusion, improving the gas discharge efficiency. The combined design of the stationary vane stage 13 and the moving vane stage 32 significantly improves the overall pumping efficiency of the molecular pump and reduces the pumping time.

[0059] In this embodiment, at least one of the motor housing 21 and the base 31 has one or more spirally extending air guide grooves 5 on its surface facing the sleeve gap 4. Each air guide groove 5 includes a starting end and a terminating end opposite each other along the extending direction. The starting end is the end of the air guide groove 5 near the output end 221, and the terminating end is the end of the air guide groove 5 away from the output end 221. From the starting end to the terminating end, the air guide groove 5 extends simultaneously along a first direction and a second direction. It should be noted that the provision of one or more spirally extending air guide grooves 5 on the surface facing the sleeve gap 4 by at least one of the motor housing 21 and the base 31 means that: the surface of the motor housing 21 facing the sleeve gap 4 has one or more spirally extending air guide grooves 5, or the surface of the base 31 facing the sleeve gap 4 has one or more spirally extending air guide grooves 5, or the surfaces of the motor housing 21 and the base 31 facing the sleeve gap 4 each have one or more spirally extending air guide grooves 5. The first direction is the direction from the output end 221 of the rotating shaft 22 to the other end of the rotating shaft 22. The second direction is opposite to the reference direction, which is the relative rotation direction of one of the motor housing 21 and the base 31 with one or more air guide grooves 5 relative to the other. When the rotating body 3 rotates, its inner wall will drive the gas molecules to move tangentially, so that the gas molecules gain a tangential velocity, and thus move the gas molecules relative to the motor housing 21 and the base 31. Since the reference direction is the relative rotation direction of one of the motor housing 21 and the base 31 with air guide grooves 5 relative to the other, the reference direction is also the rotation direction of the structure with air guide grooves 5 relative to the gas molecules; conversely, the rotation direction of the gas molecules relative to the structure with air guide grooves 5 is the second direction opposite to the reference direction. Therefore, when the extension direction of the air guide groove 5 from the starting end to the ending end is along both the first direction and the second direction, the gas molecules will flow along the air guide groove 5 and finally be discharged from the ending end of the air guide groove 5. This process creates an active, unidirectional gas transport effect, preventing corrosive, reactive, and other harmful gases from penetrating deep into the gaps in the reverse direction. This reduces the risk of performance degradation and damage to internal core components such as the shaft 22 and motor 2 due to chemical corrosion, physical deposition, or abnormal reactions. It should be noted that the above protection mechanism is entirely achieved by the reverse spiral structure of the gas guide groove 5, without relying on externally injected protective gas. Therefore, it can mitigate the problem of increased pressure and decreased vacuum at the molecular pump inlet side that might occur due to the introduction of protective gas.

[0060] Please see Figures 2 to 5In one embodiment, the outer surface of the motor housing 21 is provided with one or more air guide grooves 5. For ease of explanation and understanding, the air guide groove 5 provided on the motor housing 21 will be referred to as the first air guide groove. Providing the first air guide groove on the motor housing 21 helps reduce the overall processing difficulty and manufacturing cost. This is because the motor housing 21 is a stationary component during operation, and the precision requirements for the processing technology are relatively low, making it easy to process and implement. This effectively controls production costs and improves structural reliability and process stability. The first air guide groove extends along the first direction A shown in the figure and along the second direction B shown in the figure. As can be seen from the above, when the motor housing 21 is provided with the first air guide groove, the above reference direction is the relative rotation direction of the motor housing 21 relative to the base 31, i.e. Figures 1-3 As shown in the diagram, the second direction corresponding to the first air guide groove is clockwise. In this case, the second direction is the same as the rotation direction M of the rotating body 3. When the rotating body 3 rotates clockwise as shown in the diagram, its inner wall will drive the gas molecules to move tangentially clockwise, so that the gas molecules gain a tangential velocity in the clockwise direction. During the collision with the groove wall of the first air guide groove, the gas molecules with tangential velocity will move along the first air guide groove to the opening 41, and thus be discharged outside the sleeve gap 4, so as to reduce the damage of the pumped gas to the internal components of the motor 2.

[0061] In a specific application, please refer to Figure 2 and Figure 3 The first gas guide groove is formed by a recess on the outer surface of the motor housing 21. Directly forming the first gas guide groove by recessing the surface of the motor housing 21 is particularly suitable for applications with small fitting gaps 4. Since the first gas guide groove and the motor housing 21 are an integral structure, potential reliability issues at the connection interface are eliminated, significantly improving the structural strength and overall stability of the parts, while also enhancing the reliability of the system. The motor housing 21 may have multiple first gas guide grooves, arranged at intervals along the aforementioned second direction B. The arrangement of multiple first gas guide grooves is equivalent to forming multiple independent gas discharge channels, allowing gas within the fitting gap 4 to be discharged through these channels when the rotating body 3 rotates. This helps reduce the residence time of gas within the fitting gap 4 and also reduces the risk of pumped gas entering the fitting gap 4 during the operation of the molecular pump. This is crucial for protecting critical components such as the motor housing 21, the rotating shaft 22, and the bearings inside the motor housing 21 from corrosive gases. Preferably, the first air guide grooves arranged at intervals can be evenly distributed on the surface of the motor housing 21, so that the gas in the sleeve gap 4 can be effectively guided in all directions and have better consistency.

[0062] In another specific application, please refer to Figure 4 and Figure 5The first gas guide groove on the outer surface of the motor housing 21 can also be formed not by a recess, but by a convex structure on the outer surface of the motor housing 21. This convex structure design exhibits superior performance under molecular flow conditions, and is particularly suitable for high vacuum applications. Specifically, the molecular pump also includes at least two guide vanes 6, which are disposed on the outer surface of the motor housing 21 and extend in a spiral shape, forming the aforementioned first gas guide groove between adjacent guide vanes 6. It should be noted that the guide vanes 6 protrude from the outer surface of the motor housing 21, which is particularly suitable for applications with a large gap 4. The spiral extension structure of the guide vanes 6 can effectively guide gas molecules to form an orderly axial flow within the large gap, maintain a stable guiding effect, and prevent gas diffusion loss due to excessive gap. The molecular pump in this embodiment and Figures 2-3 The main difference between the molecular pumps shown lies in the formation of the first gas guide groove. They are otherwise largely the same and will not be elaborated upon here. When the rotating body 3 rotates clockwise as shown in the diagram, its inner wall drives the gas molecules to move tangentially clockwise, giving the gas molecules a tangential velocity in the clockwise direction. During the collision with the guide plate 6, the gas molecules move along the first gas guide groove to the aforementioned opening 41, thereby being discharged outside the aforementioned sleeve gap 4, reducing the damage caused by the pumped gas to the internal components of the motor 2.

[0063] Furthermore, the outer surface of the motor housing 21 can not only form the first air guide groove 5 by being recessed or by setting the guide plate 6, but also form a portion of the first air guide groove by being recessed and a portion of the first air guide groove by setting the guide plate 6. That is, the molecular pump includes multiple guide plates 6; the outer surface of the motor housing 21 is provided with multiple first air guide grooves, wherein a portion of the first air guide groove is formed by being recessed on the outer surface of the motor housing 21, and a portion of the first air guide groove is formed by being enclosed by two adjacent guide plates 6.

[0064] It is worth mentioning that the air guide groove 5 can be located at at least one of the large-diameter end, the tapered connecting section, and the small-diameter end of the motor housing 21. In the preferred embodiment of this application, the air guide groove 5 is located at the large-diameter end. Since the structure thickness of the large-diameter end is relatively large, it is beneficial to maintain the overall structural strength of the motor housing 21 while opening the air guide groove 5. Of course, in practical applications, the location of the air guide groove 5 is not limited to the above preferred solution and can be flexibly adjusted according to specific working conditions and design requirements.

[0065] The above description is based on the example of the motor housing 21 having an air guide groove 5. In other embodiments of this application, the air guide groove 5 may also be provided on the inner surface of the base 31 of the rotating body 3, as detailed below.

[0066] Please see Figure 6 and Figure 7In another embodiment, the inner surface of the base 31 is provided with an air guide groove 5. For ease of explanation and understanding, the air guide groove 5 provided on the inner surface of the base 31 will be referred to as the second air guide groove. The second air guide groove extends along the first direction A shown in the figure and along the second direction C shown in the figure. As can be seen from the above, when the base 31 is provided with a second air guide groove, the above-mentioned reference direction is the relative rotation direction of the base 31 with respect to the motor housing 21, that is... Figures 6-7 As shown in the diagram, the second direction C corresponding to the second air guide groove is counterclockwise. In this case, the second direction C is opposite to the rotation direction M of the rotating body 3. When the rotating body 3 rotates clockwise as shown, its inner wall causes the gas molecules to move tangentially clockwise, giving them a tangential velocity. During the collision with the wall of the second air guide groove, the gas molecules move along the second air guide groove to the opening 41, thus being discharged outside the sleeve gap 4, reducing the damage to the internal components of the motor 2 caused by the pumped gas. The spiral direction of the second air guide groove is opposite to the rotation direction of the rotating body 3, forming a unidirectional gas flow path. This guides the gas to exit from the sleeve gap 4 in a predetermined direction, reducing the possibility of reverse gas penetration and effectively isolating harmful pumped gas from contacting the internal components, preventing damage.

[0067] In a specific application, please refer to Figure 6 and Figure 7The second gas guide groove located on the base 31 is formed by a recess in the inner surface of the base 31. This recessed machining directly on the inner surface of the base 31 is particularly suitable for applications with small gaps. Since the second gas guide groove and the base 31 are an integral structure, the risk of reliability issues at the connection interface is reduced, improving the structural strength and overall stability of the parts, and enhancing the reliability of the system. The base 31 can have multiple second gas guide grooves, which are arranged at intervals along the aforementioned second direction. The arrangement of multiple second gas guide grooves is equivalent to forming multiple independent gas discharge channels, allowing the gas in the gap 4 to be discharged through these channels when the rotating body 3 rotates. This helps reduce the residence time of gas in the gap 4 and also reduces the risk of pumped gas entering the gap 4 during the operation of the molecular pump. This is of great significance for protecting critical components such as the motor housing 21, the shaft 22, and the bearings inside the motor housing 21 from corrosive gases. Preferably, the spaced-apart second gas guide grooves can be evenly distributed on the surface of the motor housing 21, allowing the gas within the sleeve gap 4 to be effectively guided in all directions with better consistency. In practical applications, parameters such as the spacing, depth, width, and helix angle of the multiple second gas guide grooves can be adjusted according to specific application requirements to adapt to different gas characteristics and operating conditions. This flexibility enables this design to be widely used in various types of molecular pumps, including turbomolecular pumps and traction molecular pumps.

[0068] In another specific application, please refer to Figure 8 and Figure 9 The second gas guide groove provided on the inner surface of the base 31 may not be formed concave, but rather formed by a protruding structure on the inner surface of the base 31. Specifically, the molecular pump also includes at least two guide vanes 6, which are disposed on the inner surface of the base 31 and extend in a spiral shape, with the aforementioned second gas guide groove formed between adjacent guide vanes 6. It should be noted that the guide vanes 6 protrude from the inner surface of the base 31, which is particularly suitable for applications with a large fitting gap 4. The spiral extension structure of the guide vanes 6 can effectively guide gas molecules to form an orderly axial flow within the large gap, maintain a stable guiding effect, and prevent gas diffusion loss due to excessive gap. The molecular pump in this embodiment and Figures 6-7 The main difference between the molecular pumps shown lies in the formation of the second gas guide groove. They are otherwise largely the same and will not be elaborated upon here. When the rotating body 3 rotates clockwise as shown in the diagram, its inner wall drives the gas molecules to move tangentially clockwise, giving the gas molecules a tangential velocity in the clockwise direction. During the collision with the guide plate 6, the gas molecules move along the second gas guide groove to the aforementioned opening 41, thereby being discharged outside the aforementioned sleeve gap 4, reducing the damage caused by the pumped gas to the internal components of the motor 2.

[0069] Furthermore, the inner surface of the base 31 can not only form a second gas guide groove by being recessed or by providing a guide plate 6, but it can also form a partial second gas guide groove by being recessed and simultaneously by providing a guide plate 6. That is, the molecular pump includes multiple guide plates 6; the inner surface of the base 31 is provided with multiple second gas guide grooves, wherein some of the second gas guide grooves are formed by being recessed on the inner surface of the base 31, and some of the second gas guide grooves are formed by being enclosed by two adjacent guide plates 6.

[0070] The above description uses examples of the motor housing 21 having a first air guide groove or the base 31 having a second air guide groove. However, it should be understood that in other embodiments of this application, the first air guide groove may be provided on the outer surface of the motor housing 21, and the second air guide groove may be provided on the inner surface of the base 31. Please refer to [reference needed]. Figure 10 and Figure 11 It should be noted that, for the first air guide groove provided on the outer surface of the motor housing 21, its corresponding second direction is the same as the rotation direction of the rotating body 3, and for the second air guide groove provided on the inner surface of the base 31, its corresponding second direction is opposite to the rotation direction of the rotating body 3. The first air guide groove and the second air guide groove are respectively provided on the outer surface of the motor housing 21 and the inner surface of the base 31 in the following ways: the outer surface of the motor housing 21 and the inner surface of the base 31 are respectively formed by indentation to form the first air guide groove and the second air guide groove; the outer surface of the motor housing 21 and the inner surface of the base 31 are respectively formed by guide plates 6; or one of the outer surface of the motor housing 21 and the inner surface of the base 31 is formed by indentation to form the first air guide groove or the second air guide groove, and the other is formed by guide plates 6.

[0071] For example, please see Figure 10In some specific applications, the outer surface of the motor housing 21 and the inner surface of the base 31 are respectively connected by guide vanes 6 to form a first air guide groove and a second air guide groove. Specifically, the molecular pump includes multiple guide vanes 6. For ease of understanding, in this embodiment, the guide vanes on the motor housing 21 are referred to as first guide vanes, and the guide vanes on the base 31 are referred to as second guide vanes. At least two first guide vanes are provided on the outer surface of the motor housing 21 and extend spirally, forming a first air guide groove between adjacent first guide vanes; at least two second guide vanes are provided on the inner surface of the base 31 and extend spirally, forming a second air guide groove between adjacent second guide vanes. Regarding the extension direction of the first and second guide vanes, please refer to the previous description of the guide vanes on the outer surface of the motor housing 21 and the guide vanes on the inner surface of the base 31, which will not be repeated here. Further, along the axial direction of the rotating shaft 22, the extension range of the first guide vanes and the extension range of the second guide vanes are staggered. This reduces the risk of interference between the first and second guide vanes during the rotation of the rotating body 3. Furthermore, compared to the overlapping axial extension range of the first and second guide vanes on the rotating shaft 22, this embodiment reduces the radial dimension of the molecular pump, thus facilitating its miniaturization. The first guide vane can be located on the side of the second guide vane opposite to the output end 221 of the rotating shaft 22. Since the assembly direction of the base 31 to the motor housing 21 is as follows... Figure 11 From a top-down direction, this arrangement allows the second guide vane to avoid crossing the first guide vane during the assembly of the base 31, thus reducing the assembly difficulty between the base 31 and the motor housing 21. Furthermore, the first guide vane can also be located on the side of the second guide vane closer to the output end 221 of the aforementioned rotating shaft 22; to facilitate the assembly of the base 31 and the motor housing 21, and to reduce the risk of interference between the first and second guide vanes, the first and second guide vanes can be staggered in the circumferential direction.

[0072] For example, please see Figure 11In other specific applications, at least one of the outer surface of the motor housing 21 and the inner surface of the base 31 is recessed to form a first air guide groove or a second air guide groove. Compared to the scheme where both the outer surface of the motor housing 21 and the inner surface of the base 31 are formed with guide vanes 6 to form the first air guide groove or the second air guide groove, this embodiment can reduce the risk of interference between the motor housing 21 and the base 31 caused by the guide vanes 6. Specifically, along the axial direction of the shaft 22, the extension ranges of the first air guide groove provided on the motor housing 21 and the second air guide groove provided on the base 31 at least partially overlap; for example, along the axial direction of the shaft 22, one end of the second air guide groove provided on the base 31 is located between the two ends of the first air guide groove provided on the motor housing 21, and the other end extends in a direction away from the output end 221 of the shaft 22 and extends beyond the first air guide groove provided on the motor housing 21. Thus, the first air guide groove provided on the motor housing 21 and the second air guide groove provided on the base 31 can together form a mechanism for continuously guiding the gas in the sleeve gap 4 to be discharged to the opening 41, thereby achieving a higher gas discharge efficiency.

[0073] Based on the above embodiments, the molecular pump can be a composite molecular pump, comprising at least one Holweck traction pump stage 7 and / or at least one Siegbahn pump stage. The Holweck traction pump stage and / or Siegbahn pump stage can be mounted on the large-diameter end of the base 31 of the rotating body 3. By integrating multiple pump stages, the advantages of pumps based on different principles can be complemented. The addition of the Holweck traction pump stage 7 and / or the Siegbahn pump stage creates a multi-stage pumping system. After initial compression, the gas can be further processed by the Holweck traction pump stage 7 and / or the Siegbahn traction pump stage, thereby significantly improving the pump's gas compression effect, achieving higher pumping speeds, better vacuum levels, and increasing the pump's back pressure, resulting in a significant improvement in the overall performance of the molecular pump. This combination method broadens the gas flow and pressure range for the composite molecular pump to maintain efficient pumping capability, meeting diverse application requirements.

[0074] In summary, the molecular pump provided in this application has a gas guide groove 5 in the sleeve gap 4 between the base 31 and the motor housing 21, which can actively guide the gas flow. Momentum is transferred to the gas molecules through the rapidly moving surface of the rotating body 3 (whose speed is comparable to the thermal motion of molecules), generating a directional guiding effect. Gas molecules in the sleeve gap 4 collide with the wall of the high-speed rotating body 3, gaining tangential velocity along the rotation direction, and are guided to the opening 41 of the sleeve gap 4 for discharge through collision with the sidewall of the gas guide groove 5. This active guidance method can more effectively control the gas flow direction and path, thereby effectively guiding and discharging the pumped gas entering the area, preventing these harmful pumped gases from contacting critical components such as the motor 2, reducing the risk of damage to internal components due to chemical corrosion, physical deposition, or extreme conditions, and improving the reliability and service life of the molecular pump. Unlike traditional gas purging technology, this application does not require the additional design of complex purging gas channels or the injection of additional purging gas. Therefore, it does not cause an increase in pressure or a decrease in vacuum at the inlet side of the molecular pump, reducing design difficulty and complexity, and lowering the manufacturing cost of adding purging gas channels.

[0075] Please see Figure 12 This application also provides a semiconductor device 200, which includes a machine base 210 and a molecular pump 100 as described in any of the above embodiments. The semiconductor device 200 can be a physical vapor deposition (PVD) device, a chemical vapor deposition (CVD) device, an epitaxial device, or an etching device, etc., and this application does not limit its specific type. The machine base 210 has an inner cavity, and the molecular pump 100 is installed in the machine base 210. The inlet of the molecular pump 100 communicates with the inner cavity of the machine base 210 to extract gas from the inner cavity, thereby achieving a high vacuum environment in the inner cavity.

[0076] Since the aforementioned molecular pump 100 is included, the semiconductor device 200 can improve the shortcomings of related technologies that require a purge gas channel for the molecular pump 100, which leads to an increase in inlet pressure and a decrease in vacuum of the molecular pump 100.

[0077] The foregoing preferred embodiments have further illustrated the objectives, technical solutions, and advantages of the present invention. It should be understood that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A molecular pump, characterized by, The molecular pump comprises: a housing provided with a cavity; a motor comprising a motor housing and a rotating shaft, the motor housing is mounted on the housing, and an output end of the rotating shaft is located in the cavity; and a rotating body comprising a base and a moving blade stage, the base is mounted on the output end and surrounds the motor housing, a sleeving gap is formed between the base and the motor housing, an opening is formed on a side of the sleeving gap away from the output end, and the moving blade stage is fixed to the base. At least one of the motor housing and the base is provided with one or more air guide grooves extending in a spiral shape on a surface thereof facing the sleeving gap, each of the air guide grooves comprises a starting end and a terminal end opposite to each other in an extending direction, the starting end is one end of the air guide groove close to the output end, and the terminal end is one end of the air guide groove away from the output end, the air guide groove extends in a first direction and a second direction from the starting end to the terminal end, the first direction is a direction in which the output end of the rotating shaft points to the other end of the rotating shaft, and the second direction is opposite to a reference direction, wherein the reference direction is a relative rotation direction of one of the motor housing and the base relative to the other. The second direction is the same as a rotation direction of the rotating body.

2. The molecular pump of claim 1, wherein, The one or more air guide grooves are formed in a recessed manner on an outer surface of the motor housing.

3. The molecular pump of claim 2, wherein, The molecular pump further comprises at least two flow guide plates, the flow guide plates are arranged on an outer surface of the motor housing and extend in a spiral shape, and one of the one or more air guide grooves is formed between two adjacent flow guide plates.

4. The molecular pump of claim 2, wherein, The motor housing is provided with a plurality of air guide grooves, and the plurality of air guide grooves arranged on the motor housing are arranged in a spaced manner along the second direction.

5. The molecular pump according to any one of claims 2 to 4, characterized in that, An inner surface of the base is provided with the one or more air guide grooves, and the second direction is opposite to a rotation direction of the rotating body.

6. The molecular pump according to any one of claims 1 to 5, characterized in that, The one or more air guide grooves arranged on the base are formed in a recessed manner on an inner surface of the base.

7. The molecular pump of claim 6, wherein, The molecular pump further comprises at least two flow guide plates, the flow guide plates are arranged on an inner surface of the base and extend in a spiral shape, and one of the one or more air guide grooves is formed between two adjacent flow guide plates.

8. The molecular pump of claim 6, wherein, The base is provided with a plurality of air guide grooves, and the plurality of air guide grooves arranged on the base are arranged in a spaced manner along the second direction.

9. The molecular pump of claim 6, wherein, The one or more air guide grooves are arranged on an outer surface of the motor housing and an inner surface of the base, and the one or more air guide grooves are formed in a recessed manner on at least one of the outer surface of the motor housing and the inner surface of the base; 10. The molecular pump according to any one of claims 1 to 9, characterized in that, In an axial direction of the rotating shaft, an extending range of the one or more air guide grooves arranged on the motor housing and an extending range of the one or more air guide grooves arranged on the base at least partially overlap. The molecular pump further comprises a plurality of flow guide plates; 11. The molecular pump according to any one of claims 1 to 9, characterized in that, At least two first flow guide plates are arranged on an outer surface of the motor housing and extend in a spiral shape, and one of the one or more air guide grooves is formed between two adjacent first flow guide plates, wherein the first flow guide plates are flow guide plates arranged on the motor housing. ​ At least two second guide vanes are arranged on the inner surface of the base and extend in a spiral shape, and one of the one or more gas guide grooves is formed between two adjacent second guide vanes, wherein the second guide vanes are guide vanes arranged on the base; The extension range of the first guide vanes is staggered with the extension range of the second guide vanes in the axial direction of the rotating shaft.

12. The molecular pump according to any one of claims 1 to 11, characterized in that, Further comprising at least one stator vane stage, the stator vane stage is located in the cavity and fixed to the shell, and the rotor vane stage and the stator vane stage are alternately distributed in the axial direction of the rotating shaft.

13. A semiconductor device, characterized by comprising: A molecular pump as claimed in any one of claims 1 to 12 is installed in a machine table. The machine table is provided with an inner cavity, and the molecular pump is installed in the machine table, and the inlet of the molecular pump is in communication with the inner cavity.

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