A semiconductor processing device and a working method

Abstract

The present invention relates to the field of semiconductor processing technology, and discloses a semiconductor processing apparatus and a working method. Among them, a first driving component is used to drive a second driving component to move between a first station and a middle station along a second direction; the first driving component is used to drive a third driving component to move between the middle station and a second station along the second direction, and the first station, the middle station and the second station are sequentially arranged at intervals along the second direction; the second driving component is used to drive a workpiece table to move between a third station and a fourth station along a first direction; the third driving component is used to drive another workpiece table to move between a fifth station and a sixth station along the first direction; the workpiece tables located at the first station and the third station and the workpiece tables located at the second station and the fifth station can mutually transfer wafers with an external mechanism; the workpiece tables located at the middle station and the fourth station and the workpiece tables located at the middle station and the sixth station can process wafers.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor processing, and in particular, to a semiconductor processing apparatus and a working method thereof. Background Art

[0002] Currently, a wafer transfer module usually uses a manipulator to transport wafers from an external machine tool or a wafer cassette to a pre-aligner. After the pre-aligner completes pre-alignment, the wafers are sent to an exposure stage by a wafer loading mechanism. After lithography is completed on the exposure stage, the wafers are taken away by the manipulator and returned to the external machine tool or the wafer cassette. Some machine tools add additional workstations on this basis to improve efficiency, but the process is generally the same.

[0003] In the currently existing dual workpiece stages, since each of the dual workpiece stages needs to move between a handover position, an alignment position, and a lithography position, and their movement paths are the same, there are likely to be conflicts in the movement structure. To solve the above problems, a stage-changing mechanism is often adopted. In the workpiece stage using the stage-changing mechanism, the linear motion axis of the workpiece stage is not fixedly connected, and the workpiece stage needs to be detached from the motion axis in a timely manner according to the working conditions and then fixed to the stage-changing mechanism. Since the workpiece stage will be in a non-fixed state, there are certain technical barriers to maintaining a high precision of the moving stage in this solution, and the stage-changing operation will inevitably increase the time consumption, thereby affecting the productivity.

[0004] Based on this, there is an urgent need for a semiconductor processing apparatus and a working method thereof to solve the above existing problems. Summary of the Invention

[0005] Based on the above, the object of the present invention is to provide a semiconductor processing apparatus and a working method thereof, which can shorten the time for moving wafers to the processing position. Without considering the processing process time, the processing efficiency can theoretically reach twice that of a conventional single workpiece stage.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] On the one hand, a semiconductor processing apparatus is provided, including:

[0008] A processing stage, which includes a first driving component, a second driving component, a third driving component, and two workpiece stages. The first driving component is used to drive the second driving component to move between a first station and a middle station along a second direction; the first driving component is used to drive the third driving component to move between the middle station and a second station along the second direction. The first station, the middle station, and the second station are sequentially spaced apart along the second direction;

[0009] The second driving component is used to drive one of the workpiece tables to move between the third station and the fourth station along the first direction; the third driving component is used to drive the other workpiece table to move between the fifth station and the sixth station along the first direction;

[0010] The workpiece tables located at the first station and the third station and the workpiece tables located at the second station and the fifth station can exchange wafers with an external mechanism; the workpiece tables located at the middle station and the fourth station and the workpiece tables located at the middle station and the sixth station can process the wafers.

[0011] As a preferred technical solution of a semiconductor processing device, the external mechanism includes two pre-aligning devices for pre-aligning wafers. The two pre-aligning devices are respectively located on one side of the first station and the second station along the first direction, and the two pre-aligning devices can respectively exchange wafers with the two workpiece tables.

[0012] As a preferred technical solution of a semiconductor processing device, the pre-aligning device includes a pre-aligner and a wafer transport mechanism. A plurality of liftable positioning posts are provided at the wafer exposure receiving position of the workpiece table, and the positioning posts are adapted to receive wafers;

[0013] The pre-aligner includes a wafer pre-aligning position and a buffer station, and the buffer station is located above the wafer pre-aligning position. The wafer pre-aligning position is used to pre-align wafers, and the buffer station is used to temporarily store wafers;

[0014] The wafer transport mechanism is used to exchange wafers between the wafer pre-aligning position and the workpiece table and between the buffer station and the workpiece table.

[0015] As a preferred technical solution of a semiconductor processing device, the wafer transport mechanism includes:

[0016] A bracket;

[0017] A first driving member disposed on the bracket;

[0018] A transport arm, the first driving member is drivingly connected to the transport arm, and the first driving member is used to drive the transport arm to move along the first direction;

[0019] The transport arm is provided with a first gripping portion and a second gripping portion for transporting wafers. The gripping centers of the first gripping portion and the second gripping portion are arranged at intervals along the first direction, and the first gripping portion and the second gripping portion are vertically spaced apart.

[0020] As a preferred technical solution of a semiconductor processing device, the first gripping part is arranged below the transfer arm, and the first gripping part is adapted to grip from the upper surface of the wafer; the second gripping part is arranged on one side of the transfer arm, and the second gripping part is adapted to grip from the lower surface of the wafer.

[0021] As a preferred technical solution of a semiconductor processing device, the first gripping part and the second gripping part are adapted to reciprocate between a wafer pre-alignment position and a wafer exposure receiving position. The first gripping part is arranged close to one side of the wafer pre-alignment position, and the second gripping part is arranged close to one side of the wafer exposure receiving position.

[0022] As a preferred technical solution of a semiconductor processing device, the first gripping part is a non-contact adsorption component arranged at the bottom of the transfer arm, and the non-contact adsorption component is adapted to non-contactingly adsorb the upper surface of the wafer; the second gripping part is a fork arm extending along a first direction arranged on the transfer arm.

[0023] As a preferred technical solution of a semiconductor processing device, the non-contact adsorption component includes a central suction cup and a plurality of adsorption parts. The adsorption parts include a plurality of second suction cups equidistant from the center of the central suction cup; the distance from the second suction cup of adjacent adsorption parts to the center of the central suction cup gradually increases; the central suction cup and the second suction cup are Bernoulli suction cups.

[0024] As a preferred technical solution of a semiconductor processing device, the transfer arm is provided with a mutually independent first air passage, a second air passage and a plurality of third air passages. The first air passage communicates with the central suction cup, the second air passage communicates with the suction nozzle, and the plurality of third air passages correspond to the plurality of adsorption parts one by one. One third air passage communicates with all the second suction cups in one adsorption part.

[0025] As a preferred technical solution of a semiconductor processing device, the extension amount of the fork arm along the first direction relative to the transfer arm is greater than the radius of the wafer, and a suction nozzle is arranged at the top of the fork arm, and the suction nozzle can adsorb the lower surface of the wafer.

[0026] As a preferred technical solution of a semiconductor processing device, the pre-aligner includes an alignment device and a detection device. The alignment device includes:

[0027] A stage, on which a long hole extending along a first direction is arranged;

[0028] A support component, the support component includes a first support column and a support member, the support member includes at least two second support columns, the second support columns are distributed on both sides of the long hole along a second direction, and the first support column and the at least two second support columns are used to support a wafer;

[0029] An adjustment component, which includes a tray and a driving member, the driving member is located below the stage, the driving member is provided with an output shaft, the output shaft passes through the long hole and is connected to the tray, the tray is used to carry and adsorb the wafer, and the driving member is used to drive the tray to move;

[0030] The detection device is arranged above the alignment device, the detection device includes a housing and a camera, the camera is installed in the housing, an avoidance hole is provided on the bottom wall of the housing, the camera can irradiate the edge of the wafer near one side of the first support column through the avoidance hole, and a wafer pre-alignment position is formed below the camera.

[0031] As a preferred technical solution of a semiconductor processing device, there are at least two groups of the support members, each group of the support members includes two of the second support columns; the support members are arranged at intervals along the first direction, and the distance between the two second support columns in the support member gradually increases along the direction away from the first support column.

[0032] As a preferred technical solution of a semiconductor processing device, the two second support columns in the support member are arranged on the upper surface of the stage and are symmetrically arranged with respect to the midline of the long hole; one end of the first support column close to the long hole is provided, and the two second support columns in the same group and the first support column are arranged in an isosceles triangle.

[0033] As a preferred technical solution of a semiconductor processing device, the support end faces of the first support column and the second support column are on the same horizontal plane.

[0034] As a preferred technical solution of a semiconductor processing device, a height adjustment device is provided below the first support column and / or the second support column, and the height adjustment device is adapted to adjust the height of the support end faces of the first support column and the second support column to the same horizontal height.

[0035] As a preferred technical solution of a semiconductor processing device, the support end faces of the two second support columns in each group of the support members are on the same horizontal plane, and the height of the second support column gradually increases along the direction away from the first support column;

[0036] The support assembly further includes a second lifting drive member, which is connected to the first support column and drives the first support column to lift to be flush with the support end surface of the second support column in one of the groups of support members, so as to horizontally support a wafer.

[0037] As a preferred technical solution of a semiconductor processing device, the detection device further includes a buffer assembly, a buffer station is formed at the buffer assembly, the buffer assembly is installed at the bottom of the housing, the buffer assembly and the camera are arranged at an interval in a first direction, and the buffer assembly includes a non-contact suction cup for adsorbing the wafer;

[0038] The buffer assembly further includes a third lifting drive member, a mounting base plate, a mounting plate and a plurality of positioning pins. The third lifting drive member is connected to the housing and is drivingly connected to the mounting base plate. The third lifting drive member is used to drive the mounting base plate to lift, and the mounting plate and the non-contact suction cup are both installed on the mounting base plate;

[0039] A plurality of the positioning pins are arranged on the mounting plate, and the plurality of positioning pins are arranged around the non-contact suction cup, and the wafer can be embedded between the plurality of positioning pins.

[0040] On the other hand, a working method is provided, which is applied to the semiconductor processing device of any one of the above. The two workpiece tables are respectively a first workpiece table and a second workpiece table. The second drive assembly is drivingly connected to the first workpiece table, and the third drive assembly is drivingly connected to the second workpiece table. The working method includes the following steps:

[0041] S10. The second workpiece table carries the wafer to be processed and moves to the middle station and the sixth station for processing. The first workpiece table moves to the first station and the third station, transports the processed wafer on the first workpiece table to an external mechanism, and at the same time the external mechanism moves the wafer to be processed onto the first workpiece table;

[0042] S20. The first workpiece table moves to the fourth station in the first direction, and the second workpiece table moves to the second station in the second direction;

[0043] S30. The first workpiece table moves to the middle station in the second direction to process the wafer to be processed carried on the first workpiece table. The second workpiece table moves to the fifth station in the first direction, transports the processed wafer on the second workpiece table to an external mechanism, and at the same time the external mechanism moves the wafer to be processed onto the second workpiece table;

[0044] S40. The second workpiece table moves to the sixth station in the first direction, and the first workpiece table moves to the fourth station in the second direction;

[0045] S50. Return to step S10 until all wafers are processed.

[0046] The beneficial effects of the present invention are as follows:

[0047] The present invention provides a semiconductor processing device and a working method. The two workpiece tables are respectively a first workpiece table and a second workpiece table. The first driving component and the second driving component cooperate to drive the first workpiece table to move to the first station, the middle station, the third station and the fourth station. The first driving component and the second driving component cooperate to drive the second workpiece table to move to the second station, the middle station, the fifth station and the sixth station. During processing, the second workpiece table carries the wafer to be processed and moves to the middle station and the sixth station for processing. The first workpiece table moves to the first station and the third station, and transports the processed wafer on the first workpiece table to an external mechanism. At the same time, the external mechanism moves the wafer to be processed onto the first workpiece table; the first workpiece table moves along the first direction to the fourth station, and the second workpiece table moves along the second direction to the second station; the first workpiece table moves along the second direction to the middle station to process the wafer to be processed carried by the first workpiece table, and the second workpiece table moves along the first direction to the fifth station, and transports the processed wafer on the second workpiece table to an external mechanism. At the same time, the external mechanism moves the wafer to be processed onto the second workpiece table; the second workpiece table moves along the first direction to the sixth station, and the first workpiece table moves along the second direction to the fourth station; a cycle is formed until all wafers are processed. In this invention, the two workpiece tables alternately move to the middle station. Although the middle station is common, since the movement times of the two workpiece tables to the middle station are staggered in the movement rhythm, the movement will not conflict. The two workpiece tables can respectively receive wafers from the external mechanism relatively independently at different stations. When one workpiece table is processing, the other workpiece table can perform wafer transfer, improving the time for the wafer to move to the processing position. Without considering the processing process time, the processing efficiency can theoretically reach twice that of the conventional single workpiece table. Description of the Drawings

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the content of the embodiments of the present invention and these drawings.

[0049] Figure 1 is a schematic structural diagram of the semiconductor processing device provided by the specific embodiment of the present invention;

[0050] Figure 2 is one of the state diagrams of the semiconductor processing device provided by the specific embodiment of the present invention;

[0051] Figure 3 It is the second state diagram of the semiconductor processing equipment provided by the specific embodiment of the present invention;

[0052] Figure 4 It is the third state diagram of the semiconductor processing equipment provided by the specific embodiment of the present invention;

[0053] Figure 5 It is the structural schematic diagram of the wafer transfer mechanism provided by the specific embodiment of the present invention;

[0054] Figure 6 It is the partial structure perspective view of the wafer transfer mechanism provided by the specific embodiment of the present invention;

[0055] Figure 7 It is the structural schematic diagram of the semiconductor processing equipment provided by the specific embodiment of the present invention;

[0056] Figure 8 It is the structural schematic diagram of the pre-aligner provided by the specific embodiment of the present invention;

[0057] Figure 9 It is the top view of the alignment device provided by the specific embodiment of the present invention;

[0058] Figure 10 It is the cross-sectional view of the detection device provided by the specific embodiment of the present invention;

[0059] Figure 11 It is the bottom view of the detection device provided by the specific embodiment of the present invention;

[0060] Figure 12 It is the first cross-sectional view of the alignment device provided by the specific embodiment of the present invention;

[0061] Figure 13 It is the second cross-sectional view of the alignment device provided by the specific embodiment of the present invention;

[0062] Figure 14 It is the partial structure schematic diagram of the detection device provided by the specific embodiment of the present invention;

[0063] Figure 15 It is the flowchart of the alignment method provided by the specific embodiment of the present invention;

[0064] Figure 16 It is the flowchart of the wafer handover method provided by the specific embodiment of the present invention;

[0065] Figure 17 It is the flowchart of the working method of the semiconductor processing equipment provided by the specific embodiment of the present invention.

[0066] The marks in the figure are as follows:

[0067] 1. Wafer transportation mechanism; 11. Bracket; 12. First driving member; 121. First linear motor; 122. Slide table; 13. Transportation arm; 131. First air passage; 132. Third air passage; 14. Fork arm; 141. Second air passage; 15. Non-contact adsorption assembly; 151. Central suction cup; 152. Adsorption member; 1521. Second suction cup; 16. Nozzle

[0068] 2. Pre-aligner

[0069] 21. Alignment device; 211. Housing; 2111. Carrier table; 21111. Long strip hole; 212. Support assembly; 2121. First support column; 2122. Support member; 21221. Second support column; 2123. Second lifting driving member; 213. Adjustment assembly; 2131. Tray; 2132. Driving member; 21321. First horizontal driving member; 21322. First lifting driving member; 21323. First rotary driving member; 213231. Output shaft

[0070] 22. Detection device; 221. Housing; 2211. Avoidance hole; 222. Camera; 223. Buffer assembly; 2231. Non-contact suction cup; 2232. Third lifting driving member; 2233. Mounting base plate; 2234. Mounting plate; 2235. Positioning pin; 22351. Tapered portion

[0071] 3. Processing table; 31. First driving assembly; 32. Second driving assembly; 33. Third driving assembly; 34. First workpiece table; 35. Second workpiece table; 36. Mounting base Detailed implementation manners

[0072] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the convenience of description, only parts related to the present invention are shown in the drawings, rather than all structures

[0073] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations

[0074] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include direct contact between the first and second features, or may include the first and second features not being in direct contact but being in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is lower than that of the second feature.

[0075] In the description of this embodiment, the orientation or positional relationships such as "upper", "lower", "left" and "right" are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operations, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0076] As Figures 1-4 shown, this embodiment provides a semiconductor processing device, which includes a processing table 3. The processing table 3 includes a first driving component 31, a second driving component 32, a third driving component 33 and two workpiece tables. The first driving component 31 is used to drive the second driving component 32 to move between a first station and a middle station along a second direction; the first driving component 31 is used to drive the third driving component 33 to move between the middle station and a second station along the second direction. The first station, the middle station and the second station are sequentially arranged at intervals along the second direction; the second driving component 32 is used to drive one workpiece table to move between a third station and a fourth station along a first direction; the third driving component 33 is used to drive the other workpiece table to move between a fifth station and a sixth station along the first direction; the workpiece tables located at the first station and the third station and the workpiece tables located at the second station and the fifth station can exchange wafers with an external mechanism; the workpiece tables located at the middle station and the fourth station and the workpiece tables located at the middle station and the sixth station can process wafers (perform wafer exposure operations). The "external mechanism" described in this application is only a proposed component name. This component is outside the main body of the processing table 3 and still belongs to the components in this semiconductor processing device, rather than a component outside this processing device.

[0077] For the convenience of example, the two workpiece tables are respectively a first workpiece table 34 and a second workpiece table 35. The first driving assembly 31 and the second driving assembly 32 cooperate to drive the first workpiece table 34 to move to the first station, the middle station, the third station and the fourth station. The first driving assembly 31 and the second driving assembly 32 cooperate to drive the second workpiece table 35 to move to the second station, the middle station, the fifth station and the sixth station. During processing, as Figure 2 shown, the second workpiece table 35 carries the wafer to be processed (exposed) and moves to the middle station and the sixth station for processing. The first workpiece table 34 moves to the first station and the third station, transports the processed wafer on the first workpiece table 34 to an external mechanism, and at the same time the external mechanism moves the wafer to be processed onto the first workpiece table 34; as Figure 3 shown, the first workpiece table 34 moves to the fourth station along the first direction, and the second workpiece table 35 moves to the second station along the second direction; as Figure 4 shown, the first workpiece table 34 moves to the middle station along the second direction to process the wafer to be processed carried by the first workpiece table 34. The second workpiece table 35 moves to the fifth station along the first direction, transports the processed wafer on the second workpiece table 35 to an external mechanism, and at the same time the external mechanism moves the wafer to be processed onto the second workpiece table 35; as Figure 3 shown, the second workpiece table 35 moves to the sixth station along the first direction, and the first workpiece table 34 moves to the fourth station along the second direction; a cycle is formed until all wafers are processed. In this invention, the two workpiece tables alternately move to the middle station. Although the middle station is common, since the times when the two workpiece tables move to the middle station are staggered in the movement rhythm, the movement will not cause conflicts. The two workpiece tables can respectively receive wafers from the external mechanism relatively independently at different stations. When one workpiece table is processing, the other workpiece table can perform wafer handover, improving the time for the wafer to move to the processing position. Without considering the processing process time, the processing efficiency can theoretically reach twice that of a conventional single workpiece table.

[0078] In this embodiment, the workpiece tables located at the middle station and the fourth station and the workpiece tables located at the middle station and the sixth station can perform exposure processing on the wafers. In this application, the first station, the second station, and the middle station described refer to the different positions where the first driving assembly 31 drives the second driving assembly 32 or drives the third driving assembly 33 to move along the second direction, Figures 2-4 the horizontal positions shown, while the third station and the fourth station are the different positions where the first workpiece table 34 on the left in Figure 2 and Figure 3 is located on the second driving assembly 32 along the first direction; the fifth station and the sixth station are the different positions where the first workpiece table 34 on the left in Figure 3 and Figure 4The different positions of the second workpiece stage 35 on the right side shown along the first direction on the third drive assembly 33, namely the third station, the fourth station, the fifth station, and the sixth station, refer to the longitudinal position of the workpiece stage. By identifying the lateral positions of the second drive assembly 32 and the third drive assembly 33 where the workpiece stage is located, and the longitudinal position of the workpiece stage (the first workpiece stage 34 and the second workpiece stage 35), the specific position of the workpiece stage can be described in the form of coordinates. For example, the "workpiece stage located at the middle station and the fourth station" mentioned above refers to Figures 2-4 the second drive assembly 32 shown is laterally located at the middle station, and the first workpiece stage 34 on the second drive assembly 32 is longitudinally located at the fourth station; as Figure 4 shown, similarly, the "workpiece stage located at the middle station and the sixth station" refers to the third drive assembly 33 being laterally located at the middle station, and the second workpiece stage 35 on the third drive assembly 33 being longitudinally located at the sixth station. Figure 2 In this embodiment, the first direction is X, the second direction is Y, and the first direction is perpendicular to the second direction.

[0079] In this embodiment, the processing table 3 includes a mounting base 36. The first drive assembly 31 is a Y-axis linear motor module, and the Y-axis linear motor module is composed of a double-slider linear motor. The double-slider linear motor is a mature structure in the prior art. The second drive assembly 32 and the third drive assembly 33 are X-axis linear motor modules. The mounting base 36 is used to provide support and a mounting reference surface for other components. The lower parts of the two X-axis linear motor modules are connected to the slider of the Y-axis linear motor module, so that when the Y-axis linear motor module moves, it can independently drive any one of the X-axis linear motor modules to move in the Y direction. The upper slider of the X-axis linear motor module is connected to the workpiece stage and can drive the workpiece stage to move in the X direction.

[0080] In this embodiment, the external mechanism includes two pre-aligning devices. The pre-aligning devices are used to pre-align the wafers. The two pre-aligning devices are respectively located on one side along the first direction of the first station and the second station, and the two pre-aligning devices can respectively transfer the wafers with the two workpiece stages. For example, when the first workpiece stage 34 is located at the first station and the third station, the exposed wafer on the first workpiece stage 34 can be transported to the pre-aligning device, and at the same time, the pre-aligning device can move the wafer to be processed and pre-aligned to the first workpiece stage 34.

[0081] Specifically, as

[0082] shown, for example Figure 7As shown in the figure, the pre-alignment device includes a pre-aligner 2 and a wafer transfer mechanism 1. A number of liftable positioning posts are provided at the wafer exposure receiving position of the worktable. It should be noted that the wafer exposure receiving position is the position where the first worktable 34 moves to the first and third stations and the second worktable 35 moves to the second and fifth stations. The positioning posts are adapted to receive wafers. The pre-aligner 2 includes a wafer pre-alignment position and a buffer station, and the buffer station is located above the wafer pre-alignment position. The wafer pre-alignment position is used to pre-align wafers, and the buffer station is used to temporarily store wafers. The wafer transfer mechanism 1 is used to transfer wafers between the wafer pre-alignment position and the worktable, and between the buffer station and the worktable.

[0083] As Figures 5-7 shown in the figure, the wafer transfer mechanism 1 of the present invention is mainly used to reciprocate between the pre-alignment position and the exposure receiving position of the lithography equipment to transfer wafers to be edge-found (finding the notch or flat edge of the wafer edge) and centered (adjusting the wafer to be centered with the center of the pre-aligner 2) by the pre-aligner 2 to the exposure receiving position of the worktable of the lithography machine for exposure or waiting for exposure. However, those skilled in the art should understand that the wafer transfer mechanism 1 of the present invention is not limited to wafer transfer between the pre-alignment position and the exposure position (or wafer exposure receiving position). As long as it is the transfer of wafers or workpieces of the same type or with the same requirements as wafers (such as substrates, etc.) between two positions, it is applicable. The wafer transfer mechanism 1 of the present invention has a bracket 11, on which a first driving member 12 and a transfer arm 13 are provided. The first driving member 12 is drivingly connected to the transfer arm 13. The first driving member 12 is used to drive the transfer arm 13 to move in the first direction, that is, from the pre-alignment position to the wafer exposure receiving position. On the transfer arm 13, a first gripping portion and a second gripping portion for transferring wafers are provided. The gripping centers of the first gripping portion and the second gripping portion are arranged at intervals in the first direction, and the first gripping portion and the second gripping portion are arranged at intervals in the vertical direction.

[0084] By arranging the first gripping portion and the second gripping portion at intervals in both the first direction and the vertical direction, it is ensured that when the two gripping portions move along with the transfer arm 13, they can independently complete the gripping of two wafers (this application is mainly used to grip wafers to be exposed and wafers that have been exposed). And there will be no movement interference between them. In order to adapt to the exposure process of wafers, the first gripping portion of the present application is arranged below the transfer portion. The first gripping portion is adapted to grip from the upper surface of the wafer (that is, the coated surface of the wafer. The gripping method of the present application is generally used for wafers with single-sided exposure. For wafers with double-sided exposure, the gripping method of the second gripping portion needs to be adapted and preferably changed to non-contact gripping). The second gripping portion is arranged on one side of the transfer arm 13. The second gripping portion is adapted to grip from the back surface of the wafer.

[0085] The second grasping part can be arranged on the side of the transfer arm 13 close to the pre-alignment position or on the side close to the exposure receiving position (i.e., the side far from the pre-alignment position). Specifically, there is no need to specifically limit on which side it is arranged, and both should be within the protection scope of the present invention. When arranged on different sides, only the moving stroke of the transfer arm 13 and the picking and placing order of the wafers before and after exposure need to be appropriately adjusted. As a preferred solution, the first grasping part and the second grasping part are adapted to reciprocate between the wafer pre-alignment position and the wafer exposure receiving position. The first driving member 12 can be a linear drive, and preferably a reciprocating linear motion. The first grasping part is arranged on the side close to the wafer pre-alignment position, and the second grasping part is arranged on the side close to the wafer exposure receiving position. The advantage of this arrangement is that when the wafer grasped by the first grasping part from the pre-alignment position is transferred to the exposure receiving position (as Figure 7 shown, the transfer arm 13 moves along the X-axis from the upper left corner to the lower right corner of the figure, moving the wafer from the pre-aligner 2 to the workpiece stage), since the second grasping part is arranged on the side of the transfer arm 13 close to the workpiece stage, the second grasping part will reach the position of the workpiece stage first. When the second grasping part reaches the wafer exposure position (or the wafer receiving position of the workpiece stage) of the workpiece stage, the exposed wafer is lifted upward by the support of the positioning posts to a height higher than that of the second grasping part. After the second grasping part continues to move to a predetermined position below the exposed wafer, the positioning posts on the workpiece stage (the positioning posts can also be called ejector pins or PINs, which are conventional techniques in the art) fall back downward to the initial position (lower than the height of the second grasping part), and the exposed wafer then falls onto the second grasping part. Then the transfer arm 13 continues to move forward. When the first grasping part at the lower part of the transfer arm 13 is directly above the exposure position (or the exposure receiving position), the transfer arm 13 stops moving. The first grasping part places the wafer to be exposed at the wafer exposure position, and then the transfer arm 13 moves in the reverse direction to transport the exposed wafer away. When the transfer arm 13 moves to the pre-alignment position, the external manipulator first transports the exposed wafer on the second grasping part away, and then controls the first grasping part to pick up the next pre-aligned wafer from the pre-alignment position.

[0086] In a specific embodiment, as Figure 5 and Figure 6As shown in the figure, this embodiment provides a wafer transfer mechanism 1. The first grasping part is a non-contact adsorption component 15 arranged at the bottom of the transfer arm 13, and the non-contact adsorption component 15 is adapted to non-contact adsorption of the upper surface of the wafer; the second grasping part is a fork arm 14 arranged on the transfer arm 13 and extending in the first direction. During operation, a non-contact adsorption component 15 is arranged at the bottom of the transfer arm 13, and the non-contact adsorption component 15 can non-contact adsorb the upper surface of the wafer to prevent scratching the upper surface of the wafer. The top of the fork arm 14 can vacuum adsorb the lower surface of the wafer. The wafer transfer mechanism 1 adsorbs the wafer by vacuum above and uses non-contact adsorption below. On the premise of using a relatively small space, it can adsorb two wafers at the same time and only use a single motion axis. It has the advantages of high space utilization rate, low cost, and high efficiency. Moreover, the first driving part 12 performs single-axis motion, and only single-axis error will be introduced under ideal conditions, so the centering and orientation accuracy of the wafer can be effectively guaranteed.

[0087] It should be noted that the upper surface of the wafer is the exposure surface, and this surface has extremely high requirements for cleanliness and contamination, etc. It does not allow the upper surface of the wafer to contact any transfer structure during transfer. Therefore, the non-contact adsorption component 15 is used to non-contact adsorb the upper surface of the wafer; while the lower surface of the wafer generally does not need to be lithographed, and the fork arm 14 can contact the lower surface of the wafer. This embodiment utilizes this characteristic of the wafer to set different types of wafer grasping structures.

[0088] In this embodiment, the first direction is X, the second direction is Y, and the first direction is perpendicular to the second direction. The first driving part 12 includes a first linear motor 121 and a slide table 122. The first linear motor 121 is drivingly connected to the slide table 122, and the transfer arm 13 is connected to the slide table 122. The transfer arm 13 can move along the first direction with the first linear motor 121.

[0089] Furthermore, the non-contact adsorption component 15 includes a central suction cup 151 and a plurality of adsorption components 152. The adsorption component 152 includes a plurality of second suction cups 1521 equidistant from the center of the central suction cup 151; the distance between the second suction cups 1521 of adjacent adsorption components 152 from the center of the central suction cup 151 gradually increases. The central suction cup 151 and the second suction cups 1521 are Bernoulli suction cups. Among them, as the distance between the second suction cups 1521 from the center of the central suction cup 151 gradually increases, the bottom of the transfer arm 13 can adsorb wafers of more sizes, improving versatility. In other embodiments, the non-contact adsorption component 15 can also adopt other non-contact adsorption methods such as electrostatic adsorption. The main purpose of using non-contact adsorption here is to prevent contamination of the upper surface of the wafer due to contact. As long as this purpose can be achieved, the specific structural form of the non-contact adsorption component 15 is not limited.

[0090] In this embodiment, a first air path 131, a second air path 141, and a plurality of third air paths 132 are independently arranged inside the transport arm 13. The first air path 131 communicates with the central suction cup 151, and the first air path 131 communicates with the central suction cup 151. The second air path 141 communicates with the suction nozzle 16. The plurality of third air paths 132 correspond to the plurality of adsorption components 152 one by one. One third air path 132 communicates with all the second suction cups 1521 inside one adsorption component 152. In this embodiment, the non-contact adsorption assembly 15 includes two adsorption components 152. Each adsorption component 152 includes four second suction cups 1521. The four second suction cups 1521 are symmetrically arranged on both sides of the central suction cup 151 along the second direction.

[0091] In this embodiment, there are two third air paths 132 in total. Among them, the first air path 131 and the two third air paths 132 are both positive pressure air paths. The first air path 131 and the two third air paths 132 can be controlled separately to meet the adsorption requirements of wafers of different sizes. The central suction cup 151 is located at the center of the wafer and is used to adsorb wafers of 2 to 4 inches; the central suction cup 151 and the adsorption component 152 close to the central suction cup 151 are grouped together and used to adsorb wafers of 5 to 8 inches; the central suction cup 151 and the adsorption component 152 far from the central suction cup 151 are grouped together and used to adsorb wafers of 12 inches. The second air path 141 is a negative pressure air path. In this embodiment, there are two fork arms 14. One ends of the two fork arms 14 are connected by a cross beam. The cross beam is connected to the suspension arm. Three suction nozzles 16 are provided at the ends of the two fork arms 14 far from the cross beam. In other embodiments, the fork arm 14 can also be one or several.

[0092] Further, the first air path 131 and the two third air paths 132 can be controlled by three independent air paths. Of course, they can also be used in combination according to needs. For example, the first air path 131 and the two third air paths 132 can be opened simultaneously to adsorb wafers with a larger thickness. The first air path 131 and the two third air paths 132 can be formed inside the transport arm 13 or connected by pipelines. Similarly, the second air path 141 can be formed inside the fork arm 14 and the transport arm 13 or connected by pipelines. The pipelines on the transport arm 13 and the fork arm 14 can be bundled and connected to the outside through a drag chain at the slide 122 to ensure smooth pipeline connection during the movement of the transport arm 13.

[0093] Preferably, the central suction cup 151 and the second suction cups 1521 are Bernoulli suction cups. When the transport arm 13 moves to directly above the wafer, the central suction cup 151 and the second suction cups 1521 can adsorb the wafer from below the transport arm 13 and ensure not to contact the surface of the wafer.

[0094] Further preferably, the extension amount of the fork arm 14 relative to the transport arm 13 in the first direction is greater than the radius of the wafer. A suction nozzle 16 is provided at the top of the fork arm 14, and the suction nozzle 16 can vacuum-adsorb the lower surface of the wafer. When ensuring that the wafer transport mechanism 1 adsorbs wafers on both the upper and lower sides, the distance between the two wafers is increased, preventing the two wafers from interfering with the external structure, improving the transfer efficiency, and enhancing the stability of the fork arm 14 in carrying the wafer. By providing the suction nozzle 16 at the top of the fork arm 14 and making the suction nozzle 16 vacuum-adsorb the lower surface of the wafer, it is ensured that the wafer on the fork arm 14 can be effectively fixed during wafer transfer, avoiding sliding or falling off during the transfer process.

[0095] Further, as Figure 7 shown, this embodiment further provides a semiconductor processing apparatus, including a workpiece table, a pre-aligner 2, and the above-mentioned wafer transport mechanism 1. The workpiece table, the pre-aligner 2, and the transport arm 13 are arranged at intervals in the first direction. A plurality of liftable positioning posts are provided at the wafer exposure receiving position of the workpiece table, and the positioning posts are adapted to receive the wafer; the pre-aligner 2 includes a wafer pre-alignment position and a buffer station, and the buffer station is located above the wafer pre-alignment position. The wafer pre-alignment position is used for pre-aligning the wafer, and the buffer station is used for temporarily storing the wafer; the workpiece table, the buffer station, and the wafer pre-alignment position are arranged at intervals in the first direction in sequence. The fork arm 14 is arranged on the side of the transport arm 13 close to the workpiece table.

[0096] During processing, the first driving member 12 drives the transport arm 13 to move above the wafer pre-alignment position and pick up the first pre-aligned wafer; the first driving member 12 drives the transport arm 13 to move in the direction close to the workpiece table, and at the same time, the positioning posts rise to lift the processed second wafer; the fork arm 14 extends under the second wafer, and the positioning posts fall back to their original positions so that the fork arm 14 adsorbs the second wafer; the first driving member 12 continues to drive the transport arm 13 to move in the direction close to the workpiece table so that the first wafer is located above the positioning posts. After the positioning posts lift to receive the first wafer and then fall back down; the first driving member 12 drives the transport arm 13 to move in the direction close to the pre-aligner 2 so that the second wafer is located below the buffer station, the transport arm 13 is located above the wafer pre-alignment position, the buffer station caches the second wafer, and the transport arm 13 picks up the next first wafer. This wafer transfer process transfers from the wafer pre-alignment position to the workpiece table, and after processing, it transfers back from the workpiece table to the wafer pre-alignment position. The transfer stroke is only one section, which is shorter than the traditional transfer stroke; in addition, when returning from the workpiece table to the wafer pre-alignment position, through the independent adsorption or support of the lower surface of the transport arm 13 and the upper surface of the fork arm 14, the wafer can be picked up from the wafer pre-alignment position and the processed wafer can be exchanged from the positioning posts respectively, so it has a higher wafer transfer working efficiency.

[0097] In this embodiment, the workpiece table is an exposure table. A wafer exposure receiving position is provided on the workpiece table. The first wafer is the wafer to be exposed, and the second wafer is the wafer that has completed exposure. The positioning posts can be driven by a lifting motor or a lifting cylinder.

[0098] Such as Figures 8-11As shown in the figure, in this embodiment, the pre-aligner 2 includes an alignment device 21 and a detection device 22. The alignment device 21 includes a stage 2111, a support assembly 212, and an adjustment assembly 213. A long hole 21111 extending in the first direction is provided on the stage 2111; the support assembly 212 includes a first support column 2121 and a support member 2122. The support member 2122 includes at least two second support columns 21221. The cooperation of at least two second support columns 21221 and one first support column 2121 realizes three-point support, which not only has good support stability, but also facilitates the adjustment of the support levelness and can effectively reduce the wear of the wafer by the support column at the support end face; the second support columns 21221 are distributed on both sides of the long hole 21111 along the second direction and are fixedly arranged on the upper surface of the stage 2111. In this embodiment, the second direction is perpendicular to the first direction in the horizontal plane. The two second support columns 21221 are symmetrically arranged on both sides of the long hole 21111. The first support column 2121 and the two second support columns 21221 are used to support the position near the edge of the wafer, so as to reserve enough space between the support columns for the tray 2131 to move; the adjustment assembly 213 includes a tray 2131 and a driving member 2132. The driving member 2132 is located below the stage 2111. The driving member 2132 is provided with an output shaft 213231. The output shaft 213231 passes through the long hole 21111 and is connected to the tray 2131. The tray 2131 is used to carry and adsorb the wafer. The driving member 2132 is used to drive the tray 2131 to lift, rotate, and move along the first direction; the detection device 22 is arranged above the alignment device 21. The detection device 22 includes a housing 221 and a camera 222. In this embodiment, the camera 222 is preferably a line array camera 222. A wafer pre-alignment position is formed below the camera 222. The side of the first support column 2121 away from the long hole 21111 is basically located at the center of the scanning area of the linear array camera 222. When wafers of different sizes are placed on the support assembly 212, the edge on the side of the first support column 2121 is basically at the center of the scanning area, so that when the wafer rotates, the contour of its edge can pass through the scanning area, and then the edge information of the wafer can be collected by the linear array camera 222. The camera 222 is installed in the housing 221. An avoidance hole 2211 is provided on the bottom wall of the housing 221. The camera 222 can irradiate the edge of the wafer located on the first support column 2121 through the avoidance hole 2211. In this embodiment, when the tray 2131 holds the wafer, it can adsorb the wafer. The adsorption method is vacuum adsorption. A plurality of vacuum nozzles 16 or vacuum grooves can be provided at the support surface of the tray 2131 for vacuum adsorption to improve the stability of the wafer. See Figure 8 , the first direction is X, the second direction is Y, and the first direction is perpendicular to the second direction.

[0099] During operation, place the wafer on the first support post 2121 and the second support post 21221. Refer to Figure 9 As shown, there is one first support post 2121 in this embodiment, which is located outside the first long hole 21111 and near the end of the long hole 21111. On Figure 9 the horizontal projection plane shown, the connecting line between the axis of the first support post 2121 and the axis of the tray 2131 is in the first direction (X direction), while the second support posts 21221 are symmetrically arranged at intervals along the second direction (Y direction) on both sides of the long hole 21111; the driving component 2132 drives the tray 2131 to move below the wafer, lift the wafer and drive the wafer to rotate a preset angle. In this embodiment, the preset angle is preferably one full circle. When the wafer rotates, the edges of the wafer sequentially pass through the scanning area of the camera 222 in the rotation direction. On Figure 9 the left side of the long hole 21111 shown, obtain the contour information of the wafer and calculate the center coordinates of the wafer, and calculate the center offset according to the center coordinates; the driving component 2132 drives the wafer so that the center of the wafer is located on one side of the center of the tray 2131 in the first direction. At this time, the offset of the center of the wafer in the Y direction is adjusted to 0, that is, the eccentric correction in the Y direction is completed; then the driving component 2132 drives the tray 2131 to descend to a height lower than the supporting end surface of the support post. At this time, the wafer is separated from the tray 2131 because it is supported by the first support post 2121 and the second support post 21221. When the tray 2131 moves downward completely away from the wafer, the driving component 2132 drives the tray 2131 to move in the first direction until the center of the tray 2131 is directly below the center of the wafer, that is, at this time, the horizontal projection of the center of the tray 2131 coincides with the center of the wafer. At this time, the X-direction offset correction of the wafer is completed; then the driving component 2132 drives the tray 2131 to move upward and lift the wafer placed on the first support post 2121 and the second support post 21221. After the wafer is separated from the support post, the tray 2131 starts vacuum adsorption to fix the wafer. At this time, the center calibration of the wafer is completed, that is, the center of the wafer lifted on the tray 2131 coincides with the center of the tray 2131 itself. For the convenience of lithography alignment, generally notch marks and flat edge marks are provided at the edges of existing wafers. During the above process, when the wafer rotates one full circle, the camera 222 not only calculates the center eccentricity of the wafer by collecting the position information of the wafer edge, but also confirms the position coordinate information of the notch or flat edge mark at the wafer edge. When the center of the wafer is corrected to coincide with the center of the tray 2131, the position information of the notch or flat edge at the wafer edge has been confirmed at this time. By rotating a certain angle forward or backward, the center point of the notch or flat edge position of the wafer is rotated to a preset position to complete the edge finding action. Preferably, the connecting line between the preset position of the notch or flat edge and the center of the tray 2131 is in the first direction.

[0100] In this embodiment, the alignment device 21 and the detection device 22 are split into two relatively independent modules. The alignment device 21 and the detection device 22 are installed independently. There is no connecting rod between the alignment device 21 and the detection device 22, and there is no occlusion in the circumferential direction of the area between the two. Moreover, after identifying the center deviation of the wafer, the adjustment component 213 can be used to achieve the pre-alignment of the wafer, without using a robotic arm for position compensation, reducing the product size, facilitating the spatial layout, and reducing the equipment cost. Finally, the wafer is supported by the first support post 2121 and two second support posts 21221. The top surfaces of the first support post 2121 and the two second support posts 21221 are flush, ensuring that the wafer remains flat during the adsorption process by the tray 2131, avoiding wafer bending or cracking caused by uneven stress. Moreover, the support of the first support post 2121 and the two second support posts 21221 has good adsorption reliability and versatility, can be applicable to the support and adsorption of wafers of different sizes, has high flexibility, is easy to maintain, and has low cost.

[0101] It should be noted that when the wafer rotates, the camera 222 obtains the contour information of the wafer and calculates the center coordinates of the wafer, which is a prior art, and the working principle and calculation method thereof will not be elaborated here.

[0102] Preferably, as Figure 8 and Figure 9 shown, the number of the support members 2122 is at least two groups. In this embodiment, seven groups are provided. The two second support posts 21221 in each group of support members 2122 are symmetrically arranged with respect to the long strip hole 21111. Each group of support members 2122 includes two second support posts 21221. The groups of support members 2122 are arranged at intervals in the first direction, and the distance between the two second support posts 21221 in the support members 2122 gradually increases in the direction away from the first support post 2121 to adapt to wafers with increasing sizes. By providing multiple groups of support members 2122, it is convenient for the support members 2122 to cooperate with the first support post 2121 to support wafers of different models. In other embodiments, each group of support members 2122 may also include more than three second support posts 21221, or even may be arranged such that there are more than two support points arranged in a fork shape at the upper end of a second support post 21221 for support. The specific support form is not limited, as long as it can cooperate with the first support post 2121 to achieve multi-point support for the wafer.

[0103] In the prior art, wafers of different sizes are concentric during pre-alignment. As a result, the positions that the camera 222 needs to scan during pre-alignment are inconsistent. Designing the camera 222 separately for each size of wafer has the advantage that the position of the camera 222 is fixed and it is convenient to use. However, this solution significantly increases the cost due to the use of several cameras 222 and has a greater impact on the space. Another solution is to add a transverse movement axis to the camera 222 so that the camera 222 of the pre-aligner 2 can exactly scan the edges of wafers of different sizes by moving the position of the camera 222. However, since this solution adds an additional movement axis to drive the movement of the camera 222, and this movement axis has high requirements for load and movement accuracy, and depending on the need to be compatible with different wafer sizes, when compatible with 2-12 inch wafers, the stroke of this movement axis can reach nearly 150 mm. Therefore, it also has a greater impact on the overall space and price. Moreover, when the camera 222 moves, it will not only affect its optimal focal plane (affecting the clarity of image acquisition), but also when moving frequently, since the reference coordinates of the camera 222 change frequently, it will increase the calculation amount and cumulative error, and thus have a greater impact on the detection accuracy.

[0104] To solve the above problems, as Figure 9 and Figure 12 shown, in this application, a base point is provided on the side of the first support column 2121 away from the long strip hole 21111 (this base point is preset by the system and the pre-alignment mark is not specifically set in the pre-aligner 2), and wafers of different size models are all placed starting from this base point. See Figure 9, as the size of the wafer increases, the right edge of the wafer gradually extends to the right. When the heights of the second support posts 21221 and the first support post 2121 in each group are the same, the second support posts 21221 under the horizontal projection of the wafer of the corresponding size will all play a supporting role. The advantage of this method is that it can support the bottom surface of the wafer at multiple points, but the disadvantage is that when adjusting the heights of a number of second support posts 21221 to be the same horizontal height, the assembly process requirements are relatively high, and once the wafer is not flat enough, it will also affect the stability of the support. Therefore, in other embodiments, the supporting end faces of the two second support posts 21221 in each group of supporting components 2122 are located on the same horizontal plane, and the heights of the second support posts 21221 in adjacent supporting components 2122 gradually increase in the direction away from the first support post 2121; for example, the increased height can be about 1-2 millimeters, and the height difference can also be other values; the support assembly 212 further includes a second lifting driving member 2123, and the second lifting driving member 2123 is connected to the first support post 2121 and drives the first support post 2121 to lift to be flush with the supporting end face of the second support post 21221 in one group of supporting components 2122 to horizontally support a wafer. In this embodiment, different groups of supporting components 2122 correspond to wafers of different models. Therefore, when supporting wafers of different models, the second lifting driving member 2123 drives the first support post 2121 to lift so that the height of the first support post 2121 is the same as that of the second support post 21221 of the corresponding supporting component 2122, ensuring that the edges of wafers of different models are all supported by one first support post 2121 and two second support posts 21221, all of which are three-point supports. For the horizontal adjustment process, since the number of support points is small, it is easier to achieve horizontal adjustment, and because the three-point support reduces the contact area with the back of the wafer, it can further reduce the wear on the back of the wafer. Furthermore, in this embodiment, when wafers of different models are all placed on the first support post 2121, the edge of the wafer close to the first support post 2121 is located at the base point position and is within the detection range of the camera 222. When the wafer rotates, the edge of the wafer under the camera 222 is always within the detection range of the camera 222, realizing the pre-alignment requirement for wafers of different specifications with only one camera 222.

[0105] Preferably, the first support post 2121 and the second support post 21221 can adsorb the wafer to improve the stability of carrying the wafer. Among them, the second support posts 21221 of different groups of supporting components 2122 can perform independent vacuum switch actions to achieve the purpose of adsorbing wafers of different sizes.

[0106] Such as Figure 9As shown, this embodiment includes a total of 7 groups of support components 2122. Along the direction away from the first support column 2121, the first group of support components 2122 and the first support column 2121 can cooperate to support a 2-inch wafer; the second group of support components 2122 and the first support column 2121 can cooperate to support a 3-inch wafer; the third group of support components 2122 and the first support column 2121 can cooperate to support a 4-inch wafer; the fourth group of support components 2122 and the first support column 2121 can cooperate to support a 5-inch wafer; the fifth group of support components 2122 and the first support column 2121 can cooperate to support a 6-inch wafer; the sixth group of support components 2122 and the first support column 2121 can cooperate to support an 8-inch wafer; the seventh group of support components 2122 and the first support column 2121 can cooperate to support a 12-inch wafer. Figure 9 The 7 circles shown in Figure 9 respectively represent the outlines of 2-inch, 3-inch, 4-inch, 5-inch, 6-inch, 8-inch, and 12-inch wafers (the above dimensions are also the most common standard wafer dimensions currently). The wafers of each model are not placed on the pre-aligner 2 of the present invention for pre-alignment at the same time. Instead, during pre-alignment, the pre-alignment work for each batch is only for one model of wafer. For example, when pre-aligning a 2-inch wafer, only the Figure 9 three support columns on the far left in Figure 9 are used for support. When pre-aligning a 12-inch wafer, the 12-inch wafer is mainly supported by the first support column 2121 on the far left and the two second support columns 21221 on the far right.

[0107] When supporting wafers of different sizes, it is preferred that the two second support columns 21221 closest to the edge of the wafer under the horizontal projection of the wafer cooperate with the first support column 2121 for support. Of course, if the heights of all the second support columns 21221 on the stage 2111 are set to be the same, and the support end faces of the first support column 2121 and the second support columns 21221 are on the same horizontal plane, then all the second support columns 21221 and the first support column 2121 under the horizontal projection of the corresponding size wafer will support the wafer. Taking a 12-inch wafer as an example, at this time Figure 9 the shown first support column 2121 and the second support columns 21221 are all located below the horizontal projection of the 12-inch wafer and jointly support the 12-inch wafer. As Figure 13 shown, the heights of the second support columns 21221 of multiple groups of support components 2122 are the same, which can simplify the product structure. During assembly, it is necessary to adjust the horizontal heights of the respective second support columns 21221 to be the same, and each second support column 21221 is fixed on the upper surface of the stage 2111.

[0108] In other embodiments, a height adjustment device is provided below the first support column 2121 and / or the second support column 21221. The height adjustment device is adapted to adjust the heights of the support end faces of the first support column 2121 and the second support column 21221 to the same horizontal height. That is to say, the heights of both the first support column 2121 and the second support column 21221 of the present application can be adjusted by the height adjustment device, or the height of one of them can be fixed, and the height of the other can be adjusted by the height adjustment device. In the above embodiments, the height adjustment of the first support column 2121 is introduced. In other embodiments, the first support column 2121 can also be fixed, and a height adjustment device can be provided below the second support column 21221. A height adjustment device can be provided separately below each second support column 21221, or all the second support columns 21221 with height differences can be adjusted as a whole. The present application does not limit this, as long as it is convenient to adjust the support effect of the support columns on the wafer; and the structure of the height adjustment device is not limited, as long as it is a mechanism or device that is convenient to control and can be driven up and down.

[0109] Further, the driving component 2132 includes a first horizontal driving member 21321, a first lifting driving member 21322, and a first rotating driving member 21323. The first horizontal driving member 21321 is drivingly connected to the first lifting driving member 21322, and the first horizontal driving member 21321 is used to drive the first lifting driving member 21322 to move in the first direction; the first lifting driving member 21322 is drivingly connected to the first rotating driving member 21323, and the first lifting driving member 21322 is used to drive the first rotating driving member 21323 to lift. The first rotating driving member 21323 is provided with an output shaft 213231, and the output shaft 213231 passes through the long hole 21111 and is connected to the tray 2131. The first rotating driving member 21323 is used to drive the tray 2131 to rotate. When the first horizontal driving member 21321 drives the first lifting driving member 21322 to move in the first direction, it further drives the tray 2131 to move in the first direction. When the first lifting driving member 21322 drives the first rotating driving member 21323 to lift, it further drives the tray 2131 to lift. In this embodiment, both the first horizontal driving member 21321 and the first lifting driving member 21322 adopt linear driving modules, and the first rotating driving member 21323 adopts a rotating motor. In this embodiment, the driving component 2132 is arranged in the housing 211, and a carrier 2111 is arranged at the top of the housing 211.

[0110] Preferably, as Figure 10 、 Figure 11 and Figure 14As shown, the detection device 22 further includes a buffer component 223. A buffer station is formed at the buffer component 223. The buffer component 223 is installed at the bottom of the housing 221. The buffer component 223 and the camera 222 are arranged at an interval in the first direction. The buffer component 223 includes a non-contact suction cup 2231 for adsorbing a wafer. When it is necessary to buffer the wafer, the non-contact suction cup 2231 adsorbs the top surface of the wafer to achieve buffering of the wafer. The non-contact suction cup 2231 has no contact with the top surface of the wafer, preventing contamination and damage to the coated surface of the wafer. Among them, the non-contact suction cup 2231 is a Bernoulli suction cup. By adding a buffer station through the buffer component 223, it is used to temporarily store or transfer the wafers after lithography is completed.

[0111] Further preferably, the buffer component 223 further includes a third lifting drive member 2232, a mounting base plate 2233, a mounting plate 2234 and a plurality of positioning pins 2235. The third lifting drive member 2232 is connected to the housing 221 and is drivingly connected to the mounting base plate 2233. The third lifting drive member 2232 is used to drive the mounting base plate 2233 to lift and lower. The mounting plate 2234 and the non-contact suction cup 2231 are both mounted on the mounting base plate 2233; a plurality of positioning pins 2235 are arranged on the mounting plate 2234. The plurality of positioning pins 2235 are arranged around the non-contact suction cup 2231, and the wafer can be embedded between the plurality of positioning pins 2235.

[0112] By driving the mounting base plate 2233 to lift and lower through the third lifting drive member 2232, the mounting plate 2234 and the non-contact suction cup 2231 can be driven to lift and lower together. When it is necessary to adsorb the wafer, when the fork arm 14 transports the wafer to directly below the Bernoulli suction cup, the third lifting drive member 2232 pushes the Bernoulli suction cup downward to a preset distance. At this time, the interval between the upper surface of the wafer and the Bernoulli suction cup is within the adsorption range of the suction cup. The Bernoulli suction cup turns on the positive pressure and adsorbs the wafer from above through the Bernoulli principle. The wafer is embedded between the plurality of positioning pins 2235, and the plurality of positioning pins 2235 limit the wafer from moving or flipping along the radial direction.

[0113] In this embodiment, the third lifting drive member 2232 can be an electric cylinder, a pneumatic cylinder or an oil cylinder, etc. In this embodiment, an electric cylinder is selected. The motor of the electric cylinder is fixed inside the housing 221 through a motor mounting bracket. The end of the output shaft 213231 of the electric cylinder is connected to the Bernoulli suction cup and is coaxially arranged. The electric cylinder drives the Bernoulli suction cup to complete the pushing out or resetting action.

[0114] Preferably, a conical portion 22351 is provided at one end of the positioning pin 2235 away from the mounting plate 2234. The side walls of several positioning pins 2235 on the side close to the non-contact suction cup 2231 enclose a first circle, and the centers of the conical portions 22351 of several positioning pins 2235 enclose a second circle. The diameter of the wafer is between the diameter of the first circle and the diameter of the second circle. After the non-contact suction cup 2231 adsorbs the wafer, the edge of the wafer abuts against the conical portion 22351 of the positioning pin 2235, thereby fixing the position of the wafer and preventing the wafer from sliding horizontally. The frictional force between the wafer and the conical portion 22351 restricts the rotation of the wafer. The number of positioning pins 2235 is preferably 3. Of course, in other embodiments, four, five, six, etc. can also be used. No matter how many positioning pins 2235 are provided, the conical portions 22351 of each positioning pin 2235 have the same structure and are evenly spaced along the circumferential direction.

[0115] Further preferably, the mounting plate 2234 is detachably connected to the mounting base plate 2233, which is convenient for replacing the mounting plate 2234 according to requirements. For wafers of different sizes, positioning pins 2235 at different positions are required. Therefore, mounting plates 2234 of different sizes are provided for replacement to use the mounting plate 2234 of the correct specification.

[0116] As Figure 15 shown, this embodiment also provides an alignment method, which is applied to the above-mentioned pre-aligner 2. The alignment method includes the following steps;

[0117] S1. Horizontally place the wafer on the first support post 2121 and two second support posts 21221; wherein the edge of the wafer located on the first support post 2121 is within the detection range of the camera 222;

[0118] S2. The driving member 2132 drives the tray 2131 to move below the wafer, lift the wafer and drive the wafer to rotate a preset angle. When the wafer rotates, the camera 222 acquires the contour information of the edge of the wafer and calculates the center coordinates of the wafer, and calculates the eccentricity of the wafer according to the center coordinates; wherein, the position where the tray 2131 lifts the wafer is approximately located at the center of the wafer, so that when the wafer rotates a preset angle, the edge of the wafer located below the camera 222 is always within the detection range of the camera 222;

[0119] S3. The driving member 2132 drives the wafer to rotate according to the eccentricity data calculated in step S2, so that the connection line between the center of the wafer and the center of the tray 2131 is in the first direction; ensure that the center of the wafer is on the moving path of the tray 2131 along the first direction;

[0120] S4, after the driving component 2132 drives the tray 2131 to descend to a level lower than the first support column 2121, the wafer is supported by the first support column 2121 and one group of second support columns 21221, and then the tray 2131 moves along the first direction to directly below the wafer, and the center of the wafer and the center of the tray 2131 are located on the same vertical line to compensate for the eccentricity of the center;

[0121] S5. The driving component 2132 drives the tray 2131 to move upward and lift the wafer to complete the center calibration of the wafer.

[0122] Furthermore, when the edge of the wafer is provided with a notch or a flat edge, step S2 also includes the camera 222 acquiring the coordinates of the notch or the flat edge; the alignment method also includes: S6, the driving component 2132 drives the tray 2131 to rotate so that the line connecting the center of the notch or the center of the flat edge and the center of the tray 2131 is located in the first direction to complete the orientation.

[0123] like Figure 16 As shown, this embodiment also provides a wafer transportation method, which is applied to the above-mentioned semiconductor processing equipment; the wafer transportation method includes the following steps:

[0124] S11, the first driving member 12 drives the first gripping portion of the transport arm 13 to move above the wafer pre-alignment position and pick up the pre-aligned first wafer;

[0125] S12, the first driving member 12 drives the second grasping portion of the transport arm 13 to move toward the workpiece table, and at the same time the positioning column rises to lift up the processed second wafer;

[0126] S13, the second grasping portion extends under the second wafer, that is, the fork arm 14 extends under the second wafer, and the positioning column falls and resets, so that the second grasping portion absorbs the second wafer;

[0127] S14, the first driving member 12 continues to drive the transport arm 13 to move toward the workpiece table so that the first wafer is located above the positioning column, and the positioning column rises to receive the first wafer and then falls back downward;

[0128] S15, the first driving member 12 drives the transport arm 13 to move towards the direction close to the pre-alignment instrument 2, so that the second wafer is located below the cache station, the first grasping portion of the transport arm 13 is located above the wafer pre-alignment position, the cache station temporarily stores the second wafer, the second grasping portion of the transport arm 13 is located below the cache station, and the transport arm 13 picks up the next first wafer.

[0129] Specifically, the transfer arm 13 moves above the wafer pre-alignment position. At this time, the non-contact adsorption component 15 below the transfer arm 13 is located directly above the wafer pre-alignment position, while the fork arm 14 extends from the wafer pre-alignment position towards the wafer exposure receiving position on the workpiece stage; the adjustment component 213 on the pre-aligner 2 jacks up the aligned wafer to a predetermined height, and the non-contact adsorption component 15 at the bottom of the transfer arm 13 adsorbs the wafer on the adjustment component 213; then the adjustment component 213 drops back to its original position, and at the same time, the transfer arm 13 drives the wafer to move towards the wafer exposure receiving position. At this time, the wafer that has been exposed at the wafer exposure receiving position is jacked up to a preset height by the positioning post on the workpiece stage, and this height is slightly higher than the upper surface of the fork arm 14. When the fork arm 14 moves directly below the exposed wafer, the positioning post on the workpiece stage drops down, and the exposed wafer falls onto the fork arm 14. The fork arm 14 starts vacuum adsorption to adsorb and fix the wafer. Then, when the transfer arm 13 continues to move until the wafer adsorbed below the transfer arm 13 is directly above the wafer exposure receiving position, the positioning post on the exposure stage jacks up the wafer to be exposed. After the positioning post holds the wafer to be exposed, it drops back to the exposure stage. The fork arm 14 on the transfer arm 13 holds the exposed wafer and returns to the wafer pre-alignment position. The non-contact adsorption component 15 below the transfer arm 13 adsorbs the next pre-aligned wafer, and the non-contact suction cup 2231 of the buffer component 223 takes away the exposed wafer on the fork arm 14. This process is repeated to improve the processing efficiency of the wafer.

[0130] In other embodiments, if the second grasping portion is provided on the side of the transfer arm 13 close to the pre-alignment position (this embodiment is not shown in the drawings and is used as Figure 7 a reference. In this case, the second grasping portion is related to Figure 7The second gripping part shown in the figure is arranged symmetrically with the transport arm 13 as the center). At this time, only appropriate adjustments need to be made to the gripping process and the moving stroke. For example, the first gripping part can grab the pre-aligned wafer from the pre-aligner 2, and then move it to the wafer exposure receiving position together with the transport arm 13. Since the second gripping part is arranged on the side of the transport arm 13 away from the wafer exposure receiving position in this case, the first gripping part must first be moved to a certain distance beyond the exposure position (or wafer exposure receiving position) (at least vertically staggered with the exposed wafer), and the positioning column on the wafer exposure receiving position then lifts the exposed wafer upward to a position higher than the second gripping part, and then the second gripping part moves to the exposed wafer. Under the wafer, the positioning column of the wafer exposure receiving position falls downward, and the exposed wafer is placed on the second grasping part; then the transport arm 13 moves in the opposite direction, and when the first grasping part moves to just above the wafer exposure receiving position, the wafer to be exposed is placed on the wafer exposure receiving position to wait for exposure, and the exposed wafer is taken by the second grasping part and moved to the pre-alignment position. When the first grasping part returns to the pre-alignment position, the second grasping part drives the exposed wafer to move beyond the pre-alignment position, and the exposed wafer is taken away by other external robots at this position.

[0131] like Figure 17 As shown, this embodiment also provides a working method, which is applied to the above-mentioned semiconductor processing equipment; the two workpiece tables are respectively a first workpiece table 34 and a second workpiece table 35, the second drive component 32 is drivingly connected to the first workpiece table 34, and the third drive component 33 is drivingly connected to the second workpiece table 35, and the working method includes the following steps:

[0132] S10, the second worktable 35 carries the wafer to be processed and moves to the middle station and the sixth station for processing, the first worktable 34 moves to the first station and the third station, the processed wafer on the first worktable 34 is transported to the external mechanism, and the external mechanism moves the wafer to be processed to the first worktable 34;

[0133] S20, the first workpiece stage 34 moves to the fourth station along the first direction, and the second workpiece stage 35 moves to the second station along the second direction;

[0134] S30, the first worktable 34 moves along the second direction to the middle station to process the wafer to be processed on the first worktable 34, the second worktable 35 moves along the first direction to the fifth station, the processed wafer on the second worktable 35 is transported to the external mechanism, and the external mechanism moves the wafer to be processed to the second worktable 35;

[0135] S40, the second workpiece stage 35 moves to the sixth station along the first direction, and the first workpiece stage 34 moves to the fourth station along the second direction;

[0136] S50. Return to step S10 until all wafers are processed.

[0137] In the first aspect, the semiconductor processing equipment occupies less space and does not require a robot for transfer. Since there is no limit on the interference diameter, the pre-aligner 2 can be arranged closer to the processing table 3, thus saving space. In the second aspect, the semiconductor processing equipment has a higher productivity. Because of its small space occupation, the path is shortened. Coupled with the omission of the journey from the robot to the pre-aligner 2, the overall movement path of the wafer is shorter, which is relatively more time-saving. Additionally, the dual workpiece table used in this embodiment can transfer wafers relatively independently from both sides. In theory, without considering the process time, the productivity of this embodiment can be more than twice that of the traditional layout scheme. In the third aspect, the semiconductor processing equipment has better safety. Since all the movements used in this embodiment are linear movements, after a runaway failure occurs, the direction of the movement can be more accurately predicted, making the loss during the failure more controllable. In the traditional scheme, due to the rotational movement of the robot, collisions are more likely to occur during a failure.

[0138] Note that the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein. Various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, it may also include more other equivalent embodiments, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A semiconductor processing equipment, characterized in that: include: A processing table (3), comprising a first drive assembly (31), a second drive assembly (32), a third drive assembly (33) and two workpiece tables, wherein the first drive assembly (31) is used to drive the second drive assembly (32) to move between a first workstation and a middle workstation along a second direction; the first drive assembly (31) is used to drive the third drive assembly (33) to move between the middle workstation and the second workstation along the second direction, and the first workstation, the middle workstation and the second workstation are arranged in sequence along the second direction; The second drive assembly (32) is used to drive one of the workpiece tables to move between a third workstation and a fourth workstation along the first direction; the third drive assembly (33) is used to drive another of the workpiece tables to move between a fifth workstation and a sixth workstation along the first direction; The worktables located at the first station and the third station and the worktables located at the second station and the fifth station can exchange wafers with external mechanisms; the worktables located at the middle station and the fourth station and the worktables located at the middle station and the sixth station can process the wafers; The external mechanism includes two pre-alignment devices, the pre-alignment devices are used to pre-align the wafer, the two pre-alignment devices are respectively located on one side of the first station and the second station along the first direction, and the two pre-alignment devices can respectively exchange the wafer with the two workpiece stages; The pre-alignment device comprises a pre-aligner (2) and a wafer transport mechanism (1), wherein the wafer exposure receiving position of the workpiece table is provided with a plurality of positioning columns capable of being raised and lowered, and the positioning columns are suitable for receiving the wafer; The pre-aligner (2) comprises a wafer pre-alignment position and a cache position, wherein the cache position is located above the wafer pre-alignment position, the wafer pre-alignment position is used to pre-align the wafer, and the cache position is used to temporarily store the wafer; The wafer transport mechanism (1) is used for mutually transferring the wafer between the wafer pre-alignment position and the workpiece stage, and between the buffer station and the workpiece stage.

2. The semiconductor processing equipment according to claim 1, characterized in that The wafer transport mechanism (1) comprises: Bracket (11); A first driving member (12) disposed on the bracket (11); A transport arm (13), wherein the first driving member (12) is drivingly connected to the transport arm (13), and the first driving member (12) is used to drive the transport arm (13) to move along the first direction; The transport arm (13) is provided with a first gripping portion and a second gripping portion for transferring the wafer, the gripping centers of the first gripping portion and the second gripping portion are arranged at intervals along the first direction, and the first gripping portion and the second gripping portion are arranged at intervals in the vertical direction.

3. The semiconductor processing equipment according to claim 2, characterized in that: The first gripping portion is arranged below the transport arm (13), and is suitable for gripping from the upper surface of the wafer; the second gripping portion is arranged on one side of the transport arm (13), and is suitable for gripping from the lower surface of the wafer.

4. The semiconductor processing equipment according to claim 2, characterized in that The first gripping part and the second gripping part are suitable for reciprocating between the wafer pre-alignment position and the wafer exposure receiving position. The first gripping part is arranged close to the wafer pre-alignment position, and the second gripping part is arranged close to the wafer exposure receiving position.

5. The semiconductor processing equipment according to claim 2, characterized in that: The first gripping portion is a non-contact adsorption component (15) arranged at the bottom of the transport arm (13), and the non-contact adsorption component (15) is suitable for non-contact adsorption of the upper surface of the wafer; the second gripping portion is a fork arm (14) arranged on the transport arm (13) and extending along the first direction.

6. The semiconductor processing equipment according to claim 5, characterized in that The non-contact adsorption component (15) comprises a central suction cup (151) and a plurality of adsorption components (152); the adsorption components (152) comprise a plurality of second suction cups (1521) equidistant from the center of the central suction cup (151); the distances between the second suction cups (1521) of adjacent adsorption components (152) and the center of the central suction cup (151) gradually increase; and the central suction cup (151) and the second suction cups (1521) are Bernoulli suction cups.

7. The semiconductor processing equipment according to claim 6, characterized in that: The transport arm (13) is provided with a first air circuit (131), a second air circuit (141) and a plurality of third air circuits (132) which are independent of each other; the first air circuit (131) is connected to the central suction cup (151); the second air circuit (141) is connected to the suction nozzle (16); a plurality of the third air circuits (132) correspond one-to-one to a plurality of the adsorption components (152); and one third air circuit (132) is connected to all the second suction cups (1521) in one adsorption component (152).

8. The semiconductor processing equipment according to claim 5, characterized in that The extension of the fork arm (14) relative to the transport arm (13) along the first direction is greater than the radius of the wafer, and a suction nozzle (16) is provided at the top of the fork arm (14), and the suction nozzle (16) is capable of sucking the lower surface of the wafer.

9. The semiconductor processing equipment according to claim 1, characterized in that The pre-aligner (2) comprises an alignment device (21) and a detection device (22), wherein the alignment device (21) comprises: A carrier (2111), wherein the carrier (2111) is provided with an elongated hole (21111) extending along the first direction; A support assembly (212), the support assembly (212) comprising a first support column (2121) and a support component (2122), the support component (2122) comprising at least two second support columns (21221), the second support columns (21221) being distributed on both sides of the long hole (21111) along the second direction, the first support column (2121) and the at least two second support columns (21221) being used to support the wafer; An adjustment component (213), comprising a tray (2131) and a driving component (2132), wherein the driving component (2132) is located below the carrier (2111), and the driving component (2132) is provided with an output shaft (213231), wherein the output shaft (213231) passes through the long hole (21111) and is connected to the tray (2131), wherein the tray (2131) is used to carry and adsorb the wafer, and the driving component (2132) is used to drive the tray (2131) to move; The detection device (22) is arranged above the alignment device (21), and comprises a shell (221) and a camera (222). The camera (222) is installed in the shell (221), and a avoidance hole (2211) is provided on the bottom wall of the shell (221). The camera (222) can illuminate the edge of the wafer on the side close to the first supporting column (2121) through the avoidance hole (2211), and the wafer pre-alignment position is formed below the camera (222).

10. The semiconductor processing equipment according to claim 9, characterized in that The support components (2122) are at least two groups, and each group of the support components (2122) comprises two second support columns (21221); the support components (2122) are arranged at intervals along the first direction, and the distance between the two second support columns (21221) in the support components (2122) gradually increases in a direction away from the first support column (2121).

11. The semiconductor processing equipment according to claim 10, characterized in that The two second support columns (21221) in the support component (2122) are arranged on the upper surface of the carrier (2111) and are symmetrically arranged with respect to the midline of the long hole (21111); the first support column (2121) is arranged close to one end of the long hole (21111), and the two second support columns (21221) in the same group are arranged in an isosceles triangle with the first support column (2121).

12. The semiconductor processing equipment according to claim 9, characterized in that The supporting end surfaces of the first supporting column (2121) and the second supporting column (21221) are on the same horizontal plane.

13. The semiconductor processing equipment according to claim 9, characterized in that A height adjustment device is provided below the first support column (2121) and / or the second support column (21221), and the height adjustment device is suitable for adjusting the heights of the support end surfaces of the first support column (2121) and the second support column (21221) to the same horizontal height.

14. The semiconductor processing equipment according to claim 10, characterized in that The supporting end surfaces of the two second supporting columns (21221) in each group of the supporting components (2122) are located on the same horizontal plane, and the height of the second supporting columns (21221) gradually increases in a direction away from the first supporting columns (2121); The support assembly (212) further comprises a second lifting drive member (2123), wherein the second lifting drive member (2123) is connected to the first support column (2121) and drives the first support column (2121) to be lifted and lowered until it is flush with the support end surface of the second support column (21221) in one group of the support components (2122) so as to horizontally support one of the wafers.

15. The semiconductor processing equipment according to claim 9, characterized in that The detection device (22) further comprises a cache component (223), the cache component (223) forms the cache station, the cache component (223) is installed at the bottom of the shell (221), the cache component (223) and the camera (222) are arranged at intervals along the first direction, and the cache component (223) comprises a non-contact suction cup (2231), and the non-contact suction cup (2231) is used to absorb the wafer; The cache assembly (223) further comprises a third lifting drive member (2232), a mounting base plate (2233), a mounting plate (2234) and a plurality of positioning pins (2235); the third lifting drive member (2232) is connected to the housing (221) and is drivingly connected to the mounting base plate (2233); the third lifting drive member (2232) is used to drive the mounting base plate (2233) to rise and fall; the mounting plate (2234) and the non-contact suction cup (2231) are both mounted on the mounting base plate (2233); A plurality of the positioning pins (2235) are arranged on the mounting plate (2234), and a plurality of the positioning pins (2235) are arranged around the non-contact suction cup (2231), and the wafer can be embedded between the plurality of the positioning pins (2235).

16. A working method, characterized in that: Applicable to a semiconductor processing device according to any one of claims 1 to 15, wherein the two workpiece tables are respectively a first workpiece table (34) and a second workpiece table (35), the second drive assembly (32) is drivably connected to the first workpiece table (34), and the third drive assembly (33) is drivably connected to the second workpiece table (35), and the working method comprises the following steps: S10, the second worktable (35) carries the wafer to be processed and moves to the middle station and the sixth station for processing, the first worktable (34) moves to the first station and the third station, the processed wafer on the first worktable (34) is transported to the external mechanism, and the external mechanism moves the wafer to be processed onto the first worktable (34); S20, the first workpiece platform (34) moves along the first direction to the fourth workstation, and the second workpiece platform (35) moves along the second direction to the second workstation; S30, the first worktable (34) moves along the second direction to the middle station to process the wafer to be processed on the first worktable (34), the second worktable (35) moves along the first direction to the fifth station to transport the processed wafer on the second worktable (35) to the external mechanism, and the external mechanism moves the wafer to be processed onto the second worktable (35); S40, the second workpiece platform (35) moves along the first direction to the sixth workstation, and the first workpiece platform (34) moves along the second direction to the fourth workstation; S50, return to step S10, until all wafers are processed.

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