Wafer loading device

Abstract

The invention provides a wafer loading device, and the device comprises an enclosed housing which is internally provided with a loading chamber; the at least one wafer bracket is arranged in the loading chamber and is used for supporting a wafer; the extraction opening is formed in the part, which encloses the shell, below the wafer bracket; the vacuumizing equipment is arranged below the extraction opening, is provided with a gas inlet directly facing the extraction opening and an impeller mounted at the gas inlet, and is used for vacuumizing the loading chamber; the valve is arranged between the extraction opening and the gas inlet, and is configured to communicate the extraction opening and the gas inlet in an open state and block the extraction opening and the gas inlet in a closed state; and the baffle plate is horizontally arranged right above the extraction opening, the upper surface of the baffle plate does not protrude out of the upper surface of the wafer in the vertical direction, and the shape of the baffle plate is designed to enable the baffle plate to shield particles which are generated during the operation of the vacuumizing equipment and the valve and rebounded by the impeller, so that the number of the particles on the upper surface of the wafer is effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and more specifically to a wafer loading device that can reduce the number of particles on the wafer surface. Background Technology

[0002] Electron beam inspection equipment is a key device in semiconductor manufacturing for inspecting chip performance and defects. During wafer inspection, the wafer needs to be transferred from storage devices such as wafer cassettes to the main vacuum chamber, thus the wafer's environment undergoes a transition from atmospheric to vacuum. To improve production efficiency and reduce vacuuming time, the main vacuum chamber is typically maintained at a high vacuum. Therefore, a dedicated wafer loading module (called a load lock) is used in the inspection equipment to achieve this transition. Each time a wafer is transferred into the main vacuum chamber, the wafer loading module changes from an atmospheric state to a vacuum state. Each time a wafer is transferred from the main vacuum chamber to a wafer cassette, the wafer loading module changes from a vacuum state to an atmospheric state.

[0003] The wafer loading module is changed from an atmospheric state to a vacuum state by a vacuum pump. When the wafer loading module changes from a vacuum state to an atmospheric state, the vacuum pump is turned off, and then the ventilation device raises the air pressure inside the wafer loading module to an atmospheric state.

[0004] However, in existing applications, it has been found that this wafer loading module poses a risk of particle contamination on the wafer surface when the vacuum equipment is running. Summary of the Invention

[0005] In view of the above problems, a wafer loading device is provided that overcomes or at least partially solves the above problems.

[0006] One object of the present invention is to reduce the number of particles on the upper surface of the wafer within the wafer loading device.

[0007] Another objective of this invention is to reduce the number of particles on the surface of the wafer while maintaining the pumping speed of the vacuum device.

[0008] In particular, according to one aspect of the present invention, a wafer loading apparatus is provided, comprising: An enclosing shell is formed inside which a loading chamber is created; At least one wafer support is disposed within the loading chamber to support the wafer; A vent is formed in a portion of the enclosure housing below the wafer support, wherein at least a portion of the vent is not covered by the wafer supported on the wafer support when viewed vertically from top to bottom. The vacuum pumping device is located below the suction port and has a gas inlet facing the suction port and an impeller installed at the gas inlet. It is used to evacuate the loading chamber. A valve, disposed between a suction port and a gas inlet, is configured to connect the suction port and the gas inlet when open and to block the suction port and the gas inlet when closed; and A baffle is horizontally positioned directly above the suction port, with its upper surface not protruding vertically from the upper surface of the wafer. The shape of the baffle is designed to block particles generated during the operation of the vacuum equipment and valves and bounced off the impeller.

[0009] Optionally, the profile of the baffle facing the edge of the wafer is adapted to the profile of the wafer.

[0010] Optionally, the profile of the baffle facing the edge of the wafer is an arc shape that matches the profile of the wafer.

[0011] Optionally, the upper surface of the baffle is flush with the upper surface of the wafer, and the edge of the baffle facing the wafer is clearance-fitted with the edge of the wafer.

[0012] Optionally, the upper surface of the baffle is lower than the lower surface of the wafer and the vertical distance between them is equal to or less than 2 mm, and in the horizontal projection of the baffle and the wafer, the edge of the baffle facing the wafer is clearance-fitted with the edge of the wafer.

[0013] Optionally, the number of wafer supports is at least two, and all wafer supports are evenly distributed horizontally around the center of the vent; and The baffle is rotationally symmetrical about the center of the air intake in the horizontal direction.

[0014] Optionally, the baffle is provided with a flow guide structure that extends vertically through the baffle. The flow guide structure is designed to allow airflow to pass vertically through the baffle while blocking particles from passing through the baffle from bottom to top.

[0015] Optionally, the flow guiding structure includes: A groove formed in the baffle and extending vertically through the baffle; and A flow guide installed in a trench; The flow guide includes at least two horizontally staggered layers of flat plates, with a predetermined vertical spacing between adjacent layers; or The flow guide is a louvered flow guide, and the louvered strips are designed with an inclination angle relative to the horizontal plane to prevent particles from passing through the baffle from bottom to top.

[0016] Optionally, there may be multiple flow guiding structures, and all flow guiding structures may be evenly distributed around the center of the air extraction port.

[0017] Optionally, the vacuum pump can be a molecular pump.

[0018] In the wafer loading apparatus provided by this invention, a vacuum pumping device and its corresponding suction port and valve are positioned diagonally below the wafer support. A baffle is horizontally positioned directly above the suction port, with its upper surface not protruding vertically from the upper surface of the wafer supported on the wafer support. The baffle is designed to block particles generated during the operation of the vacuum pumping device and valve, and bounced off the impeller of the vacuum pumping device. By setting up the baffle, particles generated during the operation of the vacuum pumping device and valve, and bounced off the impeller of the vacuum pumping device, can be blocked in the area below the wafer, preventing particles from bouncing onto the wafer and falling onto its upper surface, thereby effectively reducing the number of particles on the wafer's upper surface.

[0019] Furthermore, in the wafer loading device provided by the present invention, the contour of the baffle facing the edge of the wafer is adapted to the contour of the wafer, so that the baffle and the wafer can cooperate to form a surface area, so as to effectively block the particles rebounded by the impeller under the wafer.

[0020] Furthermore, in the wafer loading apparatus provided by this invention, the upper surface of the baffle is flush with the upper surface of the wafer, and the edge of the baffle facing the wafer is gap-fitted with the edge of the wafer. This structural design can prevent the baffle from affecting wafer transfer while ensuring the blocking effect of the combination of the baffle and the wafer on the rebounding particles as much as possible. At the same time, it keeps the baffle as far away from the air extraction port as possible in the vertical direction, thereby minimizing the impact on the air extraction speed of the vacuum device.

[0021] Furthermore, in the wafer loading device provided by this invention, the upper surface of the baffle is lower than the lower surface of the wafer, and the vertical distance between them is equal to or less than 2 mm. In the horizontal projection of the baffle and the wafer, the edge of the baffle facing the wafer is gap-fitted with the edge of the wafer. This structural design, on the one hand, can prevent the baffle from affecting wafer transfer while ensuring the blocking effect of the combination of the baffle and the wafer on rebounding particles as much as possible; on the other hand, it can better balance the vertical distance between the baffle and the wafer and the vertical distance from the baffle to the exhaust port, making it convenient for gas above the baffle to be drawn through the gap between the baffle and the wafer, while keeping the baffle as far away from the exhaust port in the vertical direction as possible, thereby minimizing the impact on the pumping speed of the vacuum device.

[0022] Furthermore, in the wafer loading device provided by the present invention, the baffle is provided with a flow guiding structure that allows airflow to pass vertically through the baffle and blocks particles from passing through the baffle from bottom to top, thereby reducing the number of particles on the upper surface of the wafer while ensuring the pumping speed of the vacuum device.

[0023] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below.

[0024] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0025] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A horizontal projection view of a wafer loading device without baffles installed; Figure 2 A vertical view of a wafer loading device without baffles installed; Figure 3 This is a schematic diagram of particle bounce in a wafer loading device without a baffle installed. Figure 4 This is a horizontal projection view of a wafer loading apparatus according to an embodiment of the present invention; Figure 5 This is a vertical view of a wafer loading apparatus according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of a baffle according to an embodiment of the present invention; Figure 7 This is an exploded view of the flow guiding structure of a baffle according to an embodiment of the present invention; Figure 8 This is a cross-sectional schematic diagram of the flow guide portion of a baffle according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the flow guide portion of a baffle according to another embodiment of the present invention. Detailed Implementation

[0026] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0027] The wafer loading module is changed from an atmospheric state to a vacuum state by evacuation. In some specific examples, this can be achieved using a dry pump and a molecular pump. During evacuation, the valve before the dry pump is opened, and the gas pressure inside the wafer loading module is reduced from atmospheric pressure to approximately 5E-2 Torr; then the valve before the molecular pump is opened, and the gas pressure inside the wafer loading module is reduced to approximately 5E-5 Torr.

[0028] When the wafer loading module changes from a vacuum state to an atmospheric state, the valves before the molecular pump and the dry pump are closed, and then the ventilation device raises the air pressure inside the wafer loading module to an atmospheric state.

[0029] To accommodate molecular pumps and improve their flow conductance, the valves upstream of the molecular pumps are typically large in diameter, often using butterfly or slide gate valves.

[0030] However, in existing applications, it has been found that the wafer loading module has resulted in particle contamination on the upper surface of the wafer when the vacuum equipment is running.

[0031] To address this issue, this invention provides a wafer loading device 100.

[0032] Figure 1 A horizontal projection view of the wafer loading device 100 without the baffle 170 installed. Figure 2 This is a vertical view of the wafer loading device 100 without the baffle 170 installed.

[0033] like Figure 1 and Figure 2 As shown, the wafer loading apparatus 100 generally includes: an enclosing housing 110 having a loading chamber formed therein; at least one wafer support 120 disposed within the loading chamber for supporting a wafer 130; a vacuum port 140 formed in a portion of the enclosing housing 110 below the wafer support 120, wherein at least a portion of the vacuum port 140 is not covered by the wafer 130 supported on the wafer support 120 when viewed vertically from top to bottom; a vacuum device 150 disposed below the vacuum port 140, having a gas inlet 151 facing the vacuum port 140 and an impeller 152 mounted at the gas inlet 151 for evacuating the loading chamber; and a valve 160 disposed between the vacuum port 140 and the gas inlet 151, configured to connect the vacuum port 140 and the gas inlet 151 in an open state and block the vacuum port 140 and the gas inlet 151 in a closed state.

[0034] It should be noted that the structure of the wafer scaffold 120 shown in the accompanying drawings is merely exemplary and does not limit the present invention. In practical applications, the number of wafer scaffolds 120 can be one, two, three, four, or even more. Those skilled in the art will understand that any suitable wafer scaffold 120 with any structure can be used, such as existing wafer scaffolds.

[0035] In this wafer loading device 100, to prevent particles generated by the rotation of the vacuum equipment 150 or the opening and closing of the valve 160 from falling onto the surface of the wafer 130 due to gravity and causing contamination, the vacuum equipment 150 and the valve 160 are arranged below the wafer 130 supported on the wafer holder 120. This allows particles generated during the operation of the vacuum equipment 150 or the opening and closing of the valve 160 to fall into the vacuum equipment 150 under gravity and be sucked away by the vacuum equipment 150, instead of falling onto the wafer 130.

[0036] However, it has been verified that this structure still poses a risk of generating particulate contamination on wafer 130.

[0037] Through research, the inventors creatively realized that this is because the particles generated during the opening and closing of valve 160, due to gravity, fall onto the high-speed rotating impeller 152 blades of the vacuum equipment 150, and then bounce within the wafer loading device 100, thus falling onto the upper surface of wafer 130. Figure 3 The dashed line in the middle shows the particle rebound path.

[0038] For this reason, see Figure 4 and Figure 5 The wafer loading apparatus 100 of the present invention may further include a baffle 170. The baffle 170 is horizontally disposed directly above the evacuation port 140 and its upper surface does not protrude vertically from the upper surface of the wafer 130. The shape of the baffle 170 is designed to block particles generated during the operation of the vacuum equipment 150 and valve 160 and bounced off by the impeller 152.

[0039] In the wafer loading apparatus 100 provided by this invention, a vacuum device and its corresponding extraction port 140 and valve 160 are disposed diagonally below the wafer support 120. A baffle 170 is horizontally disposed directly above the extraction port 140. The upper surface of the baffle 170 does not protrude vertically beyond the upper surface of the wafer 130 supported on the wafer support 120. The baffle 170 is designed to block particles generated during the operation of the vacuum device 150 and valve 160 and bounced off the impeller 152 of the vacuum device 150. By providing the baffle 170, particles generated during the operation of the vacuum device 150 and valve 160 and bounced off the impeller 152 of the vacuum device 150 can be blocked in the area below the wafer 130, preventing particles from bouncing off the wafer 130 and falling onto its upper surface. Figure 5 The dashed line shows the path of the particles blocked by the baffle 170, which effectively reduces the number of particles on the upper surface of the wafer 130.

[0040] The specific shape of the baffle 170 can be determined according to different wafer loading devices 100 and wafer transfer paths 130, so that the baffle 170 will not affect the wafer transfer after installation.

[0041] In some embodiments, see Figure 4 As shown, the contour of the baffle 170 facing the edge of the wafer 130 is adapted to the contour of the wafer 130. In this way, the baffle 170 and the wafer 130 can be matched to form a surface area to effectively block the particles bounced off the impeller 152 below the wafer 130.

[0042] Given that wafer 130 is typically circular, in some specific embodiments, the profile of baffle 170 toward the edge of wafer 130 can be an arc shape that matches the profile of wafer 130.

[0043] In some further embodiments, the upper surface of the baffle 170 is flush with the upper surface of the wafer 130, and the edge of the baffle 170 facing the wafer 130 is clearance-fitted with the edge of the wafer 130. That is, there is a small gap in the horizontal direction between the baffle 170 and the wafer 130. Specifically, the width of this gap may be less than 1 mm.

[0044] In this embodiment, the upper surface of the baffle 170 is flush with the upper surface of the wafer 130, and the edge of the baffle 170 facing the wafer 130 is clearance-fitted with the edge of the wafer 130. This structural design can, while ensuring the blocking effect of the combination of the baffle 170 and the wafer 130 on the rebounding particles as much as possible, prevent the baffle 170 from affecting the wafer transfer of the wafer 130, and at the same time keep the baffle 170 as far away from the air extraction port 140 as possible in the vertical direction, thereby minimizing the impact on the air extraction speed of the vacuum pumping device.

[0045] In some further embodiments, the upper surface of the baffle 170 is lower than the lower surface of the wafer 130 and the vertical distance between them is equal to or less than 2 mm.

[0046] In one specific embodiment, the vertical distance between the upper surface of the baffle 170 and the lower surface of the wafer 130 is 1 mm.

[0047] Furthermore, in the horizontal projection of the baffle 170 and the wafer 130, the edge of the baffle 170 facing the wafer 130 is in clearance fit with the edge of the wafer 130. Specifically, the width of this clearance can be less than 1 mm.

[0048] In this embodiment, the upper surface of the baffle 170 is lower than the lower surface of the wafer 130, and the vertical distance between them is equal to or less than 2 mm. Furthermore, in the horizontal projection of the baffle 170 and the wafer 130, the edge of the baffle 170 facing the wafer 130 is in clearance fit with the edge of the wafer 130. This structural design, on the one hand, ensures the blocking effect of the combination of the baffle 170 and the wafer 130 on the rebounding particles as much as possible, while preventing the baffle 170 from affecting the wafer 130's transfer. On the other hand, it can better balance the vertical distance between the baffle 170 and the wafer 130 and the vertical distance from the baffle 170 to the extraction port 140. This facilitates the extraction of gas above the baffle 170 through the gap between the baffle 170 and the wafer 130, while also keeping the baffle 170 as far away from the extraction port 140 in the vertical direction as possible, thereby minimizing the impact on the pumping speed of the vacuum device.

[0049] In some embodiments, the number of wafer supports 120 is at least two, and all wafer supports 120 are evenly distributed in the horizontal direction around the center of the evacuation port 140. This structure can improve the efficiency of wafer loading and transfer, and also ensure that the wafer 130 is uniformly subjected to airflow during evacuation.

[0050] Furthermore, the baffle 170 is rotated symmetrically around the center of the air extraction port 140 in the horizontal direction, so as to ensure that the airflow is uniform during extraction and avoid affecting the extraction effect.

[0051] In one specific embodiment, there are two wafer supports 120, and these two wafer supports 120 are symmetrical about the center of the vent 140 in the horizontal direction. That is, the vent 140 is located in the middle of the wafer 130 supported on the two wafer supports 120 in the horizontal direction. One wafer support 120 corresponds to one wafer placement position. Thus, the wafer loading device 100 is equipped with two wafer placement positions. One wafer placement position is used to receive the incoming wafer 130, while the other wafer placement position is used to output the wafer 130, thereby effectively balancing the size and wafer transfer efficiency of the wafer loading device 100.

[0052] Correspondingly, the baffle 170 is also symmetrical about the center of the air extraction port 140 in the horizontal direction, thereby ensuring uniform air extraction.

[0053] Figure 6 This is a schematic diagram of the structure of a baffle 170 according to an embodiment of the present invention. Figure 6 As shown, in some embodiments, the baffle 170 is provided with a flow guide structure 171 extending vertically through the baffle 170. The flow guide structure 171 is designed to allow airflow to pass vertically through the baffle 170 while blocking particles from passing through the baffle 170 from bottom to top.

[0054] In this embodiment, the baffle 170 is provided with a flow guiding structure 171 that allows airflow to pass vertically through the baffle 170 and blocks particles from passing through the baffle 170 from bottom to top, thereby reducing the number of particles on the upper surface of the wafer 130 while ensuring the pumping speed of the vacuum device.

[0055] In some embodiments, there are multiple flow guiding structures 171, and all flow guiding structures 171 are evenly distributed around the center of the air extraction port 140 to achieve uniform flow guiding, thereby further ensuring uniform air extraction.

[0056] Figure 7 This is an exploded view of the flow guiding structure 171 of the baffle 170 according to an embodiment of the present invention. Figure 7 As shown, in some embodiments, the flow guiding structure 171 may include a groove 1711 formed in and vertically penetrating the baffle 170, and a flow guiding portion 1712 installed in the groove 1711. The flow guiding portion 1712 is adapted to the shape of the groove 1711 so that at least a portion of the flow guiding portion 1712 is inserted into the groove 1711.

[0057] It should be noted that, Figure 6 and Figure 7 The number and shape of the flow guiding structures 171 shown are merely exemplary and do not limit the invention.

[0058] In some embodiments, the number of flow guiding structures 171 can be an even number, such as 2, 4, 6, etc., and the present invention does not impose a specific limitation on this.

[0059] In some embodiments, the shape of the flow guiding structure 171 (i.e., the shape of the groove 1711) can be an arc-shaped strip, a straight strip, a square, etc., and the present invention does not impose specific limitations on this.

[0060] Figure 8 This is a cross-sectional schematic diagram of the flow guide portion 1712 of the baffle 170 according to an embodiment of the present invention. Figure 8As shown, in some embodiments, the flow guide 1712 may include at least two layers of flat plates 1713 arranged alternately in the horizontal direction, and there is a preset vertical spacing between adjacent layers of flat plates 1713. When the vacuum equipment 150 is operating to evacuate gas, the gas above the baffle 170 can flow to the exhaust port 140 through the gap between the two layers of flat plates 1713, while the particles bounced off by the impeller 152 of the vacuum equipment 150 are blocked below the wafer 130 when they hit the flat plates 1713.

[0061] The plate 1713 can be fixed on the frame 1715, and the guide section 1712 is installed by inserting the frame 1715 into the groove 1711.

[0062] Figure 9 This is a schematic diagram of the flow guide portion 1712 of the baffle 170 according to another embodiment of the present invention. Figure 9 As shown, in some other embodiments, the flow guide 1712 is a louvered flow guide 1712, and the louver slats 1714 of the louver are designed with an inclination angle relative to the horizontal plane to block particles from passing through the baffle 170 from bottom to top. Optionally, the inclination angle of the louver slats 1714 relative to the horizontal plane is greater than 0° and less than 90°, such as 30°, 45°, 60°, etc.

[0063] The louvered strip 1714 can be fixed to the frame 1715, and the guide section 1712 is installed by inserting the frame 1715 into the groove 1711.

[0064] In some specific embodiments, the vacuum pump 150 is a molecular pump.

[0065] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0066] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.

Claims

1. A wafer loading device, comprising: a closed housing having a loading chamber formed therein; at least one wafer support disposed in the loading chamber for supporting a wafer; an exhaust port formed in a portion of the closed housing below the wafer support, wherein at least a portion of the exhaust port is not covered by a wafer supported on the wafer support when viewed vertically from top to bottom; a vacuumizing device disposed below the exhaust port, having a gas inlet facing the exhaust port and an impeller mounted at the gas inlet for vacuumizing the loading chamber; a valve disposed between the exhaust port and the gas inlet, configured to communicate the exhaust port and the gas inlet in an open state and to block the exhaust port and the gas inlet in a closed state; and a baffle horizontally disposed directly above the exhaust port with an upper surface thereof not protruding vertically above an upper surface of the wafer, the baffle being shaped to shield particles generated during operation of the vacuumizing device and the valve and bounced by the impeller. A profile of the baffle towards an edge of the wafer is adapted to a profile of the wafer.

2. The wafer loading device of claim 1, wherein, The profile of the baffle towards the edge of the wafer is an arc shape adapted to the profile of the wafer.

3. The wafer loading device of claim 2, wherein, The upper surface of the baffle is flush with the upper surface of the wafer, and the baffle towards the edge of the wafer is gap-fitted with the edge of the wafer.

4. The wafer carrier of claim 2, wherein, The upper surface of the baffle is lower than the lower surface of the wafer with a vertical spacing therebetween equal to or less than 2 mm, and in a horizontal projection of the baffle and the wafer, the baffle towards the edge of the wafer is gap-fitted with the edge of the wafer.

5. The wafer carrier of claim 2, wherein, The number of the wafer supports is at least two, and all the wafer supports are uniformly distributed around a center of the exhaust port in a horizontal direction; and 6. The wafer boat of claim 1, wherein, The baffle is rotationally symmetric around the center of the exhaust port in the horizontal direction. The baffle is provided with a flow guide structure vertically penetrating the baffle, the flow guide structure being designed to allow gas flow to vertically pass through the baffle and to block particles from passing through the baffle from bottom to top.

7. The wafer loading device according to any one of claims 1 to 6, wherein, The flow guide structure comprises:

8. The wafer boat of claim 7, wherein, a groove formed in the baffle and vertically penetrating the baffle; and a flow guide portion mounted in the groove; wherein the flow guide portion comprises at least two layers of flat plates staggered in a horizontal direction, and a preset vertical spacing exists between adjacent two layers of flat plates; or the flow guide portion is a louvered flow guide portion, and an inclination angle of a louver strip of the louver relative to a horizontal plane is designed to block particles from passing through the baffle from bottom to top. The number of the flow guide structures is multiple, and all the flow guide structures are uniformly distributed around the center of the exhaust port.

9. The wafer boat of claim 7, wherein, The vacuumizing device is a molecular pump.

10. The wafer carrier of claim 1, wherein, ​

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