Electromagnetic docking wafer transfer device

Abstract

The present application discloses an electromagnetic docking wafer conveying device, comprising a first driving member, a first slide rail, a transfer chamber, a dry pump, a second slide rail, a supporting member, a second driving member and three groups of electromagnets; through the second electromagnet, the first slide rail and the second slide rail are accurately and automatically aligned by electromagnetic alignment adsorption; through the cooperation of the first electromagnet and the third electromagnet, the fast and convenient switching of the supporting member driving body is realized, avoiding the high cost and complex debugging and maintenance problems of traditional high-precision manipulators, and the supporting member is fixed by electromagnetic adsorption, and the precise movement of the supporting member on the track is realized, avoiding the problems of low manual operation efficiency, high contamination risk and large position deviation; the electromagnetic docking wafer conveying device provided by the present application realizes the fully automatic transfer of wafers between the atmospheric environment and the vacuum process chamber through the coordinated design of electromagnetic adsorption, dual drive switching and track docking.

Description

Technical Field

[0001] The present application relates to the technical field of wafer manufacturing equipment, and in particular to an electromagnetic docking wafer transfer device. Background Art

[0002] In the field of semiconductor wafer manufacturing, single process chamber equipment (such as chemical vapor deposition (CVD), physical vapor deposition (PVD), etc.) usually needs to be equipped with a transfer chamber to achieve pressure isolation between the process chamber and the external environment.

[0003] Traditional single-process chamber equipment mostly relies on manual labor to deliver wafers into or take them out of the transfer chamber. This operation is not only inefficient but also prone to introducing particle contamination. The manual placement position deviation is large, which can easily affect the wafer yield.

[0004] Although large-scale equipment integrating multiple process chambers uses high-precision manipulators, its configuration cost is expensive and the debugging and maintenance procedures are complicated, making it difficult to promote and apply it in single process chamber equipment. Summary of the Invention

[0005] The purpose of this application is to overcome the deficiencies in the prior art and to provide an electromagnetic docking wafer transfer device.

[0006] The present application provides an electromagnetic docking wafer conveying device, comprising: a first driving member and a first slide rail, the first driving member is used to drive the first slide rail to move; a transfer chamber, one end of the transfer chamber is provided with a first gate valve that can be opened and closed, and the other end is provided with a second gate valve that can be opened and closed, the first gate valve faces the first slide rail, and the second gate valve is connected to the process chamber; a dry pump is used to vacuum the transfer chamber; a second slide rail is provided in the transfer chamber and is used to dock with the first slide rail; a supporting member is used to carry the wafer and can move along the first slide rail and the second slide rail; the second driving member is provided in the transfer chamber and is used to drive the supporting member to move; a first electromagnet is provided on the first slide rail and can adsorb and fix the supporting member when energized; a second electromagnet is provided at the docking end of the first slide rail or the second slide rail and can adsorb and fix the first slide rail and the second slide rail when energized so that the two are closely aligned; a third electromagnet is provided on the second driving member and can adsorb the supporting member to switch the driving body when energized.

[0007] During operation, the first electromagnet is in the energized state and fixes the supporting member on the first slide rail. After the supporting member receives the wafer to be processed, the first driving member drives the first slide rail to carry the supporting member and the wafer into the transfer chamber through the first gate valve; the second electromagnet is energized to achieve precise docking between the first slide rail and the second slide rail; the third electromagnet is energized to adsorb the supporting member, the first electromagnet is de-energized and releases the supporting member, and the second driving member drives the supporting member to transfer from the first slide rail to the second slide rail; the first driving member drives the first slide rail to evacuate the transfer chamber; after the first gate valve and the second gate valve are both in the closed state, the dry pump can evacuate the transfer chamber to facilitate the regulation of the air pressure in the transfer chamber to make it close to the working pressure of the process chamber; after the pressure relief is completed, the second driving member can drive the supporting member to carry the wafer into the process chamber through the second gate valve.

[0008] Furthermore, the second electromagnet includes a coaxially arranged fixed iron core and a movable iron core, the fixed iron core is arranged at the docking end of the first slide rail or the second slide rail, and the movable iron core is elastically connected to the center hole of the fixed iron core through a spring; the end of the movable iron core is provided with a conical positioning head; the docking end of the rail opposite to the movable iron core is provided with a conical groove adapted to the conical positioning head; when power is turned on, the movable iron core overcomes the spring force under the action of magnetic force and moves toward the conical groove, and the conical positioning head is inserted into the conical groove to realize automatic centering of the two sets of rails. At the same time, the fixed iron core is tightly adsorbed to the docking end of the rail to form a rigid connection.

[0009] Furthermore, the first electromagnet and the third electromagnet both adopt a bipolar electromagnetic structure, including alternating N-pole coils and S-pole coils, and the supporting member is correspondingly provided with an alternating permanent magnet array that matches the bipolar electromagnetic structure; when the first electromagnet or the third electromagnet is energized, by controlling the direction of the current, the adjacent coils generate magnetic fields in opposite directions, forming a magnetic locking effect with the permanent magnet array, so as to achieve horizontal positioning constraints while adsorbing the supporting member.

[0010] Furthermore, the electromagnetic docking wafer conveying device also includes: a preheating platform, which is arranged in the transfer chamber and located on one side of the second slide rail; a lifting drive component, used to drive the preheating platform to perform lifting movements; after the second drive component drives the supporting component to carry the wafer along the second slide rail to above the preheating platform, the lifting drive component drives the preheating platform to rise, and the preheating platform can support the supporting component; a groove that is adapted to the shape of the supporting component is provided on the preheating platform; after the preheating platform is raised, the supporting component can sink into the groove to facilitate the preheating platform to contact the wafer; the preheating platform is equipped with a temperature control structure, which can preheat or precool the wafer, so that the temperature of the wafer is close to the process temperature, thereby improving subsequent processing efficiency.

[0011] Furthermore, the temperature control structure includes: a cold source liquid storage tank for storing heat exchange liquid; a plate heat exchanger, the primary side inlet of the plate heat exchanger is connected to the dry pump, and the secondary side inlet is connected to the cold source liquid storage tank; a variable frequency circulation pump, connected to the cold source liquid storage tank and the plate heat exchanger; a temperature detector, used to monitor the temperature of the preheating platform; a PID temperature control module, connected to the temperature detector and the variable frequency circulation pump, which can dynamically adjust the pump flow and heat exchange time according to the detection results of the temperature detector, so as to maintain the temperature of the preheating platform at a set value; the dry pump works to generate waste heat, and the variable frequency circulation pump pumps the heat exchange liquid into the secondary side of the plate heat exchanger, and the waste heat enters the primary side of the plate heat exchanger, so that the heat exchange liquid absorbs heat and heats up; a fluid channel is provided in the preheating platform, and the heated heat exchange liquid enters the fluid channel to indirectly control the temperature of the wafer; the heat exchange liquid after heat exchange returns to the cold source liquid storage tank.

[0012] Furthermore, a connecting pipe is provided on the preheating platform; the supporting member is a hollow structure, and a socket is provided on the bottom surface of the supporting member; after the preheating platform is raised, the connecting pipe can be inserted into the socket, and the heat source or cold source used to achieve temperature control can be input into the supporting member through the connecting pipe, thereby controlling the temperature of the wafer through the supporting member.

[0013] Furthermore, the electromagnetic docking wafer transfer device also includes: a nitrogen source, which can supply nitrogen to the support part through a connecting pipe; a TEC semiconductor temperature control module, which is used to control the temperature of the nitrogen; a nitrogen recovery and purification unit, which connects the support part and the nitrogen source, and the nitrogen after heat exchange returns to the nitrogen source through the nitrogen recovery and purification unit; the nitrogen recovery and purification unit includes: a buffer tank connected in sequence, which is connected to the support part, and the reflux nitrogen containing impurities enters the buffer tank and changes from a pulse flow to a stable flow; a first filter, which is used to intercept impurity particles with a particle size greater than 0.5μm; a condensing dehumidifier, which is used to condense water vapor in the nitrogen; a second filter, which uses a PTFE membrane filter, which is used to intercept impurity particles with a particle size of 0.1-0.5μm, and can block residual oil vapor through a hydrophobic membrane; a molecular sieve adsorption tower, which is used to adsorb residual water molecules and organic gases in the nitrogen.

[0014] Furthermore, the electromagnetic docking wafer conveying device also includes a first detection component, which is arranged in the transfer chamber and is used to detect whether the wafer has reached the top of the preheating platform; after the wafer is in place, the lifting drive component drives the preheating platform to rise so that the temperature control structure can preheat the wafer. At the same time, the second electromagnet is powered off and the first slide rail exits the transfer chamber.

[0015] Furthermore, the electromagnetic docking wafer conveying device also includes a second detection part, which is used to detect whether the first slide rail enters or leaves the transfer chamber; after the first slide rail carrying the support part and the wafer enters the transfer chamber, the second electromagnet is energized to facilitate the rapid docking of the two sets of rails; after the first slide rail leaves the transfer chamber, the first gate valve is closed and the dry pump is started.

[0016] Furthermore, the electromagnetic docking wafer conveying device also includes a third driving member, which is used to drive the first driving member and the first slide rail to move between at least two workstations; after the first driving member and the first slide rail send a group of supporting members into a transfer chamber, the first slide rail withdraws and is dispatched by the third driving member to another transfer chamber to perform the transfer task.

[0017] The present application provides an electromagnetic docking wafer conveying device, comprising a first driving member, a first slide rail, a transfer chamber, a dry pump, a second slide rail, a supporting member, a second driving member and three groups of electromagnets. When the first electromagnet is energized, the supporting member can be fixed on the first slide rail by magnetically adsorbing the supporting member; when the third electromagnet is energized, the supporting member can be magnetically adsorbed to achieve the switching of the driving body from the first driving member to the second driving member; the second electromagnet is used to calibrate the docking position of the first slide rail and the second slide rail, ensuring that the two are aligned while ensuring that the docking ends of the two are in a stable connection state, so as to achieve cross-track movement of the supporting member. The electromagnetic docking wafer conveying device provided by the present application uses a second electromagnet and electromagnetic alignment adsorption to achieve precise automatic alignment of the first slide rail and the second slide rail, solving the problems of easy damage, insufficient alignment accuracy and time-consuming of traditional track rigid docking; through the cooperation of the first electromagnet and the third electromagnet, it can achieve fast and convenient switching of the supporting part driving body, avoiding the high cost and complex debugging and maintenance of traditional high-precision manipulators, and use electromagnetic adsorption to fix the supporting part, and achieve precise movement of the supporting part on the track, avoiding the problems of low manual operation efficiency, high contamination risk and large position deviation; the electromagnetic docking wafer conveying device provided by the present application realizes the fully automatic transfer of wafers between the atmospheric environment and the vacuum process chamber through the coordinated design of electromagnetic adsorption, dual drive switching and track docking, while ensuring high-precision transmission, reducing equipment costs and maintenance difficulty, and improving transmission efficiency and yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic structural diagram of an electromagnetic docking wafer transfer device provided in this application;

[0019] Figure 2 for Figure 1 A top view of the structure of the electromagnetic docking wafer transfer device shown;

[0020] Figure 3 for Figure 1 A front view of the structure of the electromagnetic docking wafer transfer device shown;

[0021] Figure 4 A schematic structural diagram of another electromagnetic docking wafer transfer device provided in this application. DETAILED DESCRIPTION

[0022] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0023] The present application provides an electromagnetic docking wafer transfer device, comprising: a first driving member 11 and a first slide rail 12, the first driving member 11 is used to drive the first slide rail 12 to move; a transfer chamber 20, one end of the transfer chamber 20 is provided with a first gate valve 21 that can be opened and closed, and the other end is provided with a second gate valve 22 that can be opened and closed, the first gate valve 21 faces the first slide rail 12, and the second gate valve 22 is connected to the process chamber 1; a dry pump is used to evacuate the transfer chamber 20; a second slide rail 31 is provided in the transfer chamber 20, and is used to dock with the first slide rail 12; a supporting member 13 is used to support The wafer is carried and can move along the first slide rail 12 and the second slide rail 31; the second driving member 32 is arranged in the transfer chamber 20, and is used to drive the supporting member 13 to move; the first electromagnet is arranged on the first slide rail 12, and can adsorb and fix the supporting member 13 when powered on; the second electromagnet is arranged at the docking end of the first slide rail 12 or the second slide rail 31, and can adsorb and fix the first slide rail 12 and the second slide rail 31 when powered on, so that the two are closely aligned; the third electromagnet is arranged on the second driving member 32, and can adsorb the supporting member 13 when powered on to switch the driving body.

[0024] It should be explained that the end of the first slide rail 12 pointing to the second slide rail 31 is its docking end, and the end of the second slide rail 31 pointing to the first slide rail 12 is its docking end; when the two rails are docked, the docking ends of the two rails abut against each other.

[0025] For details, please refer to Figure 1 and Figure 2 In the illustrated embodiment, the first drive member 11 (which can be a linear motor, ball screw module, etc.) is horizontally fixed to the left exterior of the transfer chamber 20. Its movable end is rigidly connected to the first slide rail 12, which extends horizontally toward the first gate valve 21. The first electromagnet is embedded in the first slide rail 12, facing the bottom surface of the support member 13.

[0026] The transfer chamber 20 is arranged in a square frame. A first gate valve 21 (which can be a pneumatic gate valve) is located on the left side of the transfer chamber 20, and a second gate valve 22 (which can be a pneumatic gate valve) is located on the right side. The right side of the second gate valve 22 interfaces with the process chamber 1 (e.g., a CVD reaction chamber). A second horizontally extending slide rail 31 is installed within the transfer chamber 20. The first and second slide rails 12 and 31 are aligned on the same horizontal axis. A second electromagnet is located at the left end of the second slide rail 31. (In other embodiments, the second electromagnet can be located at the right end of the first slide rail 12, or at both facing ends of the two slide rails.)

[0027] A second driving member 32 (a driving structure such as a linear motor or a ball screw module may also be used) is further provided in the transfer chamber 20 . The second driving member 32 is located on one side of the second slide rail 31 . A third electromagnet is provided on the movable end of the second driving member 32 . The third electromagnet corresponds to the side position of the supporting member 13 .

[0028] The support member 13 is flat. Its bottom surface, facing the first electromagnet, and its side surface, facing the second electromagnet, are equipped with alignment structures (such as the permanent magnet array described below, or a block of ferromagnetic material, such as pure iron or silicon steel) to facilitate permanent magnet adsorption. The support member 13 slides along the first and second slide rails 12 and 31, with its motion path passing through the first gate valve 21, the transfer chamber 20, and the second gate valve 22.

[0029] During operation, the first electromagnet is energized, fixing the supporting member 13 on the first slide rail 12. After the supporting member 13 receives the wafer to be processed, the first driving member 11 drives the first slide rail 12 to carry the supporting member 13 and the wafer into the transfer chamber 20 through the first gate valve 21; the second electromagnet is energized to achieve precise docking of the first slide rail 12 and the second slide rail 31; the third electromagnet is energized to adsorb the supporting member 13, the first electromagnet is de-energized, releasing the supporting member 13, and the second driving member 32 drives the supporting member 13 to transfer from the first slide rail 12 to the second slide rail 31; the first driving member 11 drives the first slide rail 12 to evacuate the transfer chamber 20; after the first gate valve 21 and the second gate valve 22 are both in the closed state, the dry pump can evacuate the transfer chamber 20 to facilitate regulating the air pressure in the transfer chamber 20 to make it close to the working pressure of the process chamber 1; after the pressure relief is completed, the second driving member 32 can drive the supporting member 13 to carry the wafer into the process chamber 1 through the second gate valve 22.

[0030] In simple terms, when the first electromagnet is energized, it magnetically attracts the supporting member 13, thereby fixing the supporting member 13 to the first slide rail 12; when the third electromagnet is energized, it magnetically attracts the supporting member 13, thereby realizing the switching of the driving body from the first driving member 11 to the second driving member 32.

[0031] The second electromagnet is used to calibrate the docking position of the first slide rail 12 and the second slide rail 31 to ensure that the two are aligned and the butt ends thereof are firmly connected to facilitate the cross-rail movement of the supporting member 13 .

[0032] In a specific embodiment, referring to Figure 2 The supporting member 13 is initially located on the first slide rail 12 and is fixed by the energized first electromagnet. After the supporting member 13 receives the wafer, the first driving member 11 is activated, driving the first slide rail 12 to translate to the right, and enters the transfer chamber 20 through the opened first gate valve 21. At this time, the right end of the first slide rail 12 is facing the left end of the second slide rail 31. After the first slide rail 12 enters the transfer chamber 20 and approaches the second slide rail 31, the control system triggers the second electromagnet to energize. The second electromagnet attracts the alignment structure at the right end of the first slide rail 12 to calibrate the relative position of the two sets of rails. When the alignment structure on the side of the supporting member 13 approaches the third electromagnet, the third electromagnet is energized to attract the supporting member 13. At the same time, the first electromagnet is de-energized and releases the supporting member 13. The second driving member 32 is activated, and the third electromagnet can be used to drive the supporting member 13 to slide from the first slide rail 12 to the second slide rail 31. After support member 13 leaves first slide rail 12, the second electromagnet is de-energized, and first driver 11 drives first slide rail 12 out of transfer chamber 20. First and second gate valves 21 and 22 close, and a dry pump evacuates transfer chamber 20, reducing the pressure from atmospheric pressure to a level close to or equal to the process pressure. Once pressure relief is complete, second gate valve 22 opens, and second driver 32 propels support member 13, carrying the wafer, to the right. The wafer passes through second gate valve 22 and enters process chamber 1, where it is removed from the receiving structure for processing.

[0033] The electromagnetic docking wafer conveying device provided in the present application uses a second electromagnet and electromagnetic alignment adsorption to achieve precise automatic alignment of the first slide rail 12 and the second slide rail 31, solving the problems of easy damage, insufficient alignment accuracy and time-consuming of traditional track rigid docking; through the cooperation of the first electromagnet and the third electromagnet, the fast and convenient switching of the driving body of the supporting member 13 is achieved, avoiding the high cost and complex debugging and maintenance of traditional high-precision manipulators, and the use of electromagnetic adsorption to fix the supporting member 13 and achieve precise movement of the supporting member 13 on the track, avoiding the problems of low manual operation efficiency, high contamination risk and large position deviation; the electromagnetic docking wafer conveying device provided in the present application realizes the fully automatic transfer of wafers between the atmospheric environment and the vacuum process chamber through the coordinated design of electromagnetic adsorption, dual drive switching and track docking, while ensuring high-precision transmission, reducing equipment costs and maintenance difficulties, and improving transmission efficiency and yield.

[0034] In one embodiment, the second drive element 32 utilizes a synchronous belt assembly. The second drive element 32 comprises a driving wheel, a driven wheel, a synchronous belt, and a wheel drive element. The driving wheel and driven wheel are rotatably disposed within the transfer chamber 20, with their axes aligned at the same height and spaced apart in a direction parallel to the second slide rail 31. The synchronous belt is sleeved over the driving wheel and the driven wheel, and its inner surface is provided with trapezoidal teeth that mesh with the grooves of the driving and driven wheels. A third electromagnet is provided on the synchronous belt. The wheel drive element (which can be an electric motor, etc.) has a fixed end disposed outside the transfer chamber 20 and a movable end that penetrates the transfer chamber 20 and connects to the driving wheel. To ensure a tight connection, the coupling between the wheel drive element and the driving wheel utilizes a bellows-type vacuum coupling.

[0035] After the third electromagnet attracts the support member 13, the wheel drive mechanism activates, driving the active wheel clockwise through the coupling. The toothed belt meshes with the gears and moves rightward, driving the third electromagnet, which is fixed to the belt, to translate horizontally toward the second slide rail 31 and the second gate valve 22. After the wafers are processed, the wheel drive mechanism reverses, causing the third electromagnet to move horizontally toward the first slide rail 12 and the first gate valve 21. After the support member 13 enters the first slide rail 12 and is attracted and fixed by the first electromagnet, the third electromagnet is de-energized and the active drive is switched back to active, allowing the first drive mechanism 11 to remove the wafers.

[0036] The second drive element 32 utilizes a synchronous belt assembly. The meshing structure of the trapezoidal teeth and the wheel grooves achieves zero-slip transmission, ensuring the translational accuracy of the support element 13 and meeting the stringent positioning accuracy requirements of semiconductor wafer transfer. Furthermore, the synchronous belt offers high transmission efficiency, low noise, and requires no frequent lubrication, effectively reducing the risk of contamination within the cavity. Positioning the wheel drive element outside the cavity and connecting it to the active wheel within the cavity via a bellows-type vacuum coupling not only simplifies heat dissipation and maintenance of the drive system by utilizing the space outside the cavity (no need to disrupt the vacuum environment within the cavity during maintenance), but also prevents heat and oil generated by the drive element from contaminating the transfer cavity 20. The bellows' elastic sealing structure also effectively controls leakage rates, ensuring the vacuum and cleanliness within the cavity.

[0037] Optionally, the second electromagnet includes a coaxially arranged fixed iron core and a movable iron core, the fixed iron core is arranged at the docking end of the first slide rail 12 or the second slide rail 31, and the movable iron core is elastically connected to the center hole of the fixed iron core through a spring; a conical positioning head is provided at the end of the movable iron core; a conical groove adapted to the conical positioning head is provided on the docking end of the rail opposite to the movable iron core; when power is turned on, the movable iron core overcomes the spring force under the action of magnetic force and moves toward the conical groove, and the conical positioning head is inserted into the conical groove to realize automatic centering of the two sets of rails. At the same time, the fixed iron core is tightly adsorbed to the docking end of the rail to form a rigid connection.

[0038] Specifically, the fixed core is made of laminated high-permeability silicon steel sheets and is located at the butt joint of the first rail 12 or the second rail 31 (for example, the butt joint of the first rail 12 is equipped with a second electromagnet, while the butt joint of the second rail 31 is equipped with a tapered groove). The fixed core has a central hole with one end open. An electromagnetic coil is located within or around the fixed core, surrounding the central hole. When energized, the electromagnetic coil generates a magnetic field.

[0039] The movable core is made of the same material as the fixed core and is cylindrical in shape. Its diameter is smaller than the inner diameter of the center hole. It is inserted into the center hole and can move axially within it. The front end of the movable core is machined into a tapered locating head (with a taper angle of 15-30°), which extends from the open end of the center hole. The rear end of the movable core is elastically connected to the bottom of the center hole via a spring. The tapered locating head of the movable core is coaxially aligned with the tapered groove on the opposite slide rail.

[0040] The fixed core and the movable core are coaxially arranged. In the initial state, the second electromagnet is de-energized, and the movable core is held in the center hole by a spring. When the rails are docked, the second electromagnet is energized, magnetizing the fixed core and the movable core. The movable core, attracted by the magnetic field of the fixed core, overcomes the elastic resistance of the spring and moves forward (the coil on the fixed core generates an axial magnetic field when energized. According to Ampere's law, the front end of the fixed core is the north pole, while the front end of the movable core is magnetized to the south pole. The magnetic force of opposite poles attracts each other, driving the movable core forward). The conical positioning head protrudes from the center hole and eventually inserts into the opposite conical groove. At the same time, the end face of the fixed core is tightly adsorbed to the docking surface of the other slide rail. After the support member 13 is transferred, the second electromagnet is de-energized, the magnetic field disappears, and the movable core retreats back into the center hole under the elastic potential energy of the spring. The conical positioning head disengages from the conical groove, and the two rails are disconnected.

[0041] In this embodiment, the tapered locating head and the inclined surface of the tapered groove form a geometric guide. When the movable core is inserted, the inclined surface automatically aligns the centerlines of the two slide rails, ensuring centering accuracy. Furthermore, the end face of the fixed core and the mating surface of the other rail (equipped with an alignment structure) form magnetic attraction under the influence of a magnetic field. The attraction force can reach tens of Newtons, ensuring a rigid connection after docking to resist transmission vibration.

[0042] Optionally, the movable iron core is configured in the shape of a circular axis, and an axially extending spiral guide groove is provided on the circumference of the movable iron core. When the movable iron core is inserted into the conical groove, the spiral guide groove can guide the residual gas to be discharged along the spiral path, avoiding the formation of an air gap that affects the adsorption force.

[0043] In one specific embodiment, the movable core is in the shape of a circular shaft, with two to four equally spaced spiral guide grooves machined onto its circumference. The grooves have a pitch of 1.5 to 3 mm, a groove depth of 0.3 to 0.5 mm, a groove width of 0.8 to 1.2 mm, and a helix angle (the angle between the groove line and the axis) of 25 to 45°. For example, a movable core with a diameter of 10 mm may have three spiral grooves with a pitch of 2 mm and a groove depth of 0.4 mm, with a rectangular or semicircular cross-section.

[0044] When the movable iron core moves toward the conical groove under the action of electromagnetic force, the spiral guide groove is inserted into the conical groove along with the movable iron core. At this time, the residual gas in the enclosed space between the movable iron core and the conical groove is compressed and forced to be discharged outward along the spiral guide groove.

[0045] During traditional flat docking, residual gas creates an air gap, increasing magnetic resistance and reducing the attraction force. The geometry of the spiral guide groove forces the gas to rotate, helping to increase flow rate and accelerate exhaust efficiency. The presence of the spiral guide groove also allows a small amount of gas to be compressed and retained within the tapered groove, thus avoiding the formation of a continuous air gap between the docking adsorption surfaces. Eliminating the air gap effectively improves the magnetic attraction between the fixed core end face and the other rail docking surface, ensuring docking rigidity and the seismic stability of the rail.

[0046] Optionally, the first electromagnet and the third electromagnet both adopt a bipolar electromagnetic structure, including alternating N-pole coils and S-pole coils, and the supporting member 13 is correspondingly provided with an alternating permanent magnet array that matches the bipolar electromagnetic structure; when the first electromagnet or the third electromagnet is energized, by controlling the direction of the current, the adjacent coils generate magnetic fields in opposite directions, forming a magnetic locking effect with the permanent magnet array, so as to achieve horizontal positioning constraint while adsorbing the supporting member 13.

[0047] It's important to clarify that the "north pole" and "south pole" mentioned here simply distinguish the two types of coils, not that they possess inherent polarity. Coils are typically wound around a silicon steel core using enameled wire. By controlling the direction of the current, adjacent coils produce different magnetic polarities (according to Ampere's law, when current flows into one end of the coil, that end forms the south pole, and the other end forms the north pole; when the current direction reverses, the magnetic polarity reverses accordingly), resulting in alternating north-pole and south-pole coils.

[0048] Simply put, currents in opposite directions are passed through adjacent coils, making them the north pole and the south pole respectively. When the first electromagnet or the third electromagnet is energized, an "NSNS" or "SNSN" alternating magnetic field can be formed.

[0049] The permanent magnet array on the support member 13 uses neodymium iron boron permanent magnets, arranged in an alternating "SNSN" or "NSNS" pattern. The permanent magnet array matches the alternating magnetic field of the coils. For example, when an electromagnet generates an "NSNS" alternating magnetic field through at least two sets of coils, the corresponding permanent magnet array is arranged in an alternating "SNSN" pattern.

[0050] The permanent magnets are secured to the support member 13 using countersunk screws or high-strength adhesive. The array's length covers the active area of ​​the coils. When the coils are energized to generate an alternating magnetic field, each south pole of the permanent magnet array attracts a north pole coil, and each north pole attracts a south pole coil, creating a synergistic effect at multiple attraction points. Because support member 13 is simultaneously secured by multiple attraction points, if horizontal displacement occurs, the difference in attraction between the two poles generates a restoring torque, forcing support member 13 back to its equilibrium position.

[0051] The "opposite poles attract each other" between the alternating magnetic poles to form a magnetic locking effect. This corresponding adsorption not only provides vertical adsorption force, but also forms a restraining torque in the horizontal direction, thereby improving the horizontal positioning accuracy of the supporting member 13.

[0052] The electromagnetic docking wafer transfer device provided by the present application also includes: a preheating platform 41, which is arranged in the transfer chamber 20 and is located on one side of the second slide rail 31; a lifting drive member 42 for driving the preheating platform 41 to perform lifting movement; after the second drive member 32 drives the supporting member 13 to move along the second slide rail 31 to the top of the preheating platform 41, the lifting drive member 42 drives the preheating platform 41 to rise, and the preheating platform 41 can support the supporting member 13; the preheating platform 41 is provided with a support member 13; The supporting member 13 is adapted to the groove of the shape; after the preheating platform 41 is raised, the supporting member 13 can be sunk into the groove so that the preheating platform 41 can contact the wafer; the preheating platform 41 is equipped with a temperature control structure 50, which can preheat or precool the wafer so that the temperature of the wafer is close to the process temperature, thereby improving the subsequent processing efficiency; after the process is completed, the wafer is allowed to fall back into the preheating platform 41, and the preheating platform 41 can also heat or cool the wafer for subsequent transfer and processing.

[0053] For details, please refer to Figures 1 to 3In the illustrated embodiment, the preheating platform 41 is arranged in a circular shape that matches the shape of the wafer. A circular embedding groove is provided at the bottom of the transfer chamber 20. In the non-lifting state, at least part of the preheating platform 41 is in the circular embedding groove to avoid interfering with the translation of the support member 13 and the wafer in the chamber. The upper surface of the preheating platform 41 is provided with a groove that matches the shape of the support member 13. The size of the groove is slightly larger than the outer contour of the support member 13 to ensure that the support member 13 can be smoothly embedded. The temperature control structure 50 is integrated into the interior of the preheating platform 41 and includes a heating element, a cooling element and a temperature sensor. The lifting drive member 42 adopts a servo electric cylinder, the cylinder body of which is installed outside the transfer chamber 20 and is fixed to the bottom surface of the transfer chamber 20 through a flange. The screw shaft penetrates the cavity and is connected to the preheating platform 41. A metal bellows is also provided between the lifting drive member 42 and the transfer chamber 20 to ensure the sealing of the connection. By installing the electric cylinder outside the cavity, there is no need to destroy the vacuum environment in the transfer cavity 20 during maintenance. The motor and encoder can be debugged by simply removing the outer protective cover. This can also prevent the lubricating grease inside the built-in drive from evaporating under vacuum and contaminating the cavity. In addition, the heat generated by the electric cylinder during operation can be dissipated outside the cavity to avoid interfering with the temperature control of the wafer in the cavity.

[0054] More specifically, Figure 2 In the illustrated embodiment, the portion of the support member 13 that contacts the wafer is designed as a dual-finger structure, with two rectangular fingers spaced side by side. The fingers are made of high-purity quartz or alumina ceramic (quartz / ceramic materials do not degas under vacuum and have excellent insulation properties, preventing electrostatic adsorption of particles), with a surface roughness of Ra ≤ 0.2μm to avoid scratching the wafer. The upper surface of the fingers is a flat contact area for bonding to the back of the wafer. The small contact area between the fingers and the wafer reduces the risk of contamination on the back of the wafer. The gap between the fingers allows the receiving structure (such as the ejector pin) in the process chamber 1 to pass through when it is raised, facilitating wafer transfer.

[0055] Correspondingly, Figure 2 In the embodiment shown, two parallel rectangular grooves are provided on the upper surface of the preheating platform 41, and the size and position of the grooves are strictly matched to those of the fingers. The double groove design can form two-point support, so that the swing amplitude of the support member 13 on the preheating platform 41 is smaller, thereby preventing the wafer from being offset due to vibration during the temperature control process, so that the support member 13 can continue to transfer the wafer accurately and stably after preheating or precooling is completed. A 0.5mm thick fluororubber pad is also laid at the bottom of the groove, which has both buffering and anti-slip functions. When the preheating platform 41 rises under the drive of the lifting drive member 42, the two fingers of the support member 13 fall into the corresponding grooves respectively, and the upper surface of the fingers is flush with the edge of the groove, or the fingers are completely immersed in the groove, so that the wafer falls on the preheating platform 41 and sticks to the preheating platform 41, thereby achieving efficient heat conduction.

[0056] In a specific embodiment, referring to Figure 2, the second driving member 32 drives the supporting member 13 to move to the right along the second slide rail 31 to just above the preheating platform 41. After the wafer is in place, the lifting driving member 42 starts, pushing the preheating platform 41 up, so that the supporting member 13 falls into the groove. At this time, the upper surface of the preheating platform 41 is in direct contact with the lower surface of the wafer. Depending on the process requirements, the preheating platform 41 can heat up or cool down the wafer. During temperature control, the dry pump is vacuumed. After the pressure relief is completed, the second gate valve 22 is opened, the lifting driving member 42 pulls the preheating platform 41 down, and the second driving member 32 is started again to deliver the temperature-controlled wafer to the process chamber 1.

[0057] Preheating or precooling the wafers on the preheating platform 41 not only takes advantage of the vacuum pumping phase, preventing the transfer chamber 20 from being idle, but also allows the wafer temperature to approach the process temperature, helping to accelerate the process. After the processed wafers are returned to the transfer chamber 20, they can be heated or cooled again on the preheating platform 41 to bring the wafer temperature close to the requirements of downstream processing or other steps.

[0058] In one embodiment, a nickel-chromium alloy heating belt or a ceramic electric heating rod is provided in the preheating platform 41. The current is adjusted by a PID temperature control module to achieve preheating temperature control of 100°C-300°C. The heating rate can reach 8°C / min, which is suitable for processes with high requirements for temperature uniformity (such as PECVD).

[0059] In another embodiment, a TEC semiconductor temperature control module is integrated in the preheating platform 41, which realizes wide temperature range control of -20°C to 80°C through the Peltier effect, and the cooling rate reaches 10°C / min.

[0060] In another embodiment, the preheating platform 41 is filled with a phase change material (such as a paraffin-based solid-liquid phase change material with a phase change temperature of 80°C-120°C). The latent heat of the phase change of the material is used to maintain a constant temperature. A small amount of heating wire is used to compensate for heat dissipation, so that the temperature fluctuation can be controlled within ±0.5°C, which is suitable for photolithography processes that require extremely high temperature stability.

[0061] This application does not limit the specific configuration of the temperature control structure 50 .

[0062] In a specific embodiment, the temperature control structure 50 includes: a cold source liquid storage tank for storing heat exchange liquid; a plate heat exchanger, the primary side inlet of the plate heat exchanger is connected to the dry pump, and the secondary side inlet is connected to the cold source liquid storage tank; a variable frequency circulation pump, connected to the cold source liquid storage tank and the plate heat exchanger; a temperature detector, used to monitor the temperature of the preheating platform 41; a PID temperature control module, connected to the temperature detector and the variable frequency circulation pump, which can dynamically adjust the pump flow and heat exchange time according to the detection results of the temperature detector, so as to maintain the temperature of the preheating platform 41 at a set value; the dry pump works to generate waste heat, and the variable frequency circulation pump pumps the heat exchange liquid into the secondary side of the plate heat exchanger, and the waste heat enters the primary side of the plate heat exchanger, so that the heat exchange liquid absorbs heat and heats up; a fluid channel is provided in the preheating platform 41, and the heated heat exchange liquid enters the fluid channel to indirectly control the temperature of the wafer; the heat exchange liquid after heat exchange returns to the cold source liquid storage tank.

[0063] Specifically, the components in the temperature control structure 50 form a closed-loop system of "cold source liquid storage tank→plate heat exchanger→variable frequency circulation pump→preheating platform 41→cold source liquid storage tank" through pipelines and circuits.

[0064] The cold source liquid storage tank stores heat exchange liquid (such as thermal oil or water) and is connected to the inlet of the variable frequency circulation pump via a pipe. The primary inlet of the plate heat exchanger is connected to the waste heat outlet of the dry pump, and the secondary inlet is connected to the outlet of the variable frequency circulation pump. The outlet of the plate heat exchanger is connected to the fluid channels of the preheating platform 41 via a pipe. The fluid channels within the preheating platform 41 are arranged in a serpentine pattern to increase the heat exchange area and extend the heat exchange path.

[0065] The waste heat gas (or liquid) generated during dry pump operation flows through a pipe into the primary flow channel of the plate heat exchanger. The plate heat exchanger's heat exchange plates feature a herringbone corrugated design, creating turbulent flow in the waste heat fluid to improve the heat transfer coefficient. Simultaneously, driven by a variable frequency circulation pump, the heat exchange liquid on the secondary side flows in the reverse direction through the secondary flow channel, exchanging heat with the primary waste heat. The heated heat exchange liquid is pressurized by the variable frequency circulation pump and enters the fluid channel of the preheating platform 41, indirectly transferring heat to the wafer. A temperature detector (such as a PT100 thermistor) is embedded in the center of the preheating platform 41 and connected via a cable to a PID temperature control module, which controls the frequency of the variable frequency circulation pump.

[0066] In one specific embodiment, during operation, the dry pump generates waste heat at 80°C-100°C, which enters the primary side of the plate heat exchanger. A variable-frequency circulating pump pumps thermal oil at 25°C from the cold source reservoir into the secondary side, exchanging heat with the primary waste heat, raising the oil temperature to 80°C-120°C. The hot oil then flows into the fluid channels of the preheating platform 41, preheating the wafers. After heat exchange, the oil, cooled to 40°C-80°C, returns to the reservoir, completing the circulation. A temperature detector monitors the temperature of the preheating platform 41 in real time, and a PID temperature control module dynamically adjusts the frequency of the variable-frequency circulating pump based on deviations (for example, increasing the operating frequency and liquid flow rate if the temperature falls below the set value), ensuring that the heat exchange liquid temperature fluctuates within ±1°C. The heat exchanged liquid returns to the reservoir through the reflux port, completing the closed-loop circulation.

[0067] This implementation method realizes the utilization of waste heat from the dry pump. Through the integrated design of waste heat recovery and precise temperature control, it not only solves the problem of energy waste in semiconductor equipment, but also improves the wafer preheating efficiency through efficient heat exchange, which helps to increase single-cavity production capacity while reducing equipment operating costs.

[0068] Optionally, the temperature control structure 50 also includes a heat dissipation and cooling device connected to the primary outlet of the plate heat exchanger. Waste heat from the primary side enters the heat dissipation and cooling device, which contains a finned radiator. Once the waste heat enters the device, it is forced to dissipate through convection by an axial fan, further reducing the waste heat temperature to below 30°C before being discharged.

[0069] The installation of a heat dissipation and air cooling device can, on the one hand, prevent the dry pump from overheating due to waste heat backflow, ensuring that the dry pump bearing temperature is always below 70°C, thereby extending its service life; on the other hand, it can reduce the primary side outlet temperature of the plate heat exchanger and maintain the secondary side heat exchange temperature difference at 40°C-50°C, thereby ensuring that the plate heat exchanger always operates within the high-efficiency range.

[0070] Optionally, the heat exchange liquid is a 40% ethylene glycol aqueous solution.

[0071] The freezing point of a 40% ethylene glycol aqueous solution is -24°C, significantly lower than that of pure water (0°C). This prevents the heat exchange fluid from freezing under low-temperature conditions (such as during the cooling phase), potentially preventing the fluid channels from freezing and cracking. For example, when the system needs to cool wafers from 300°C to 50°C, the heat exchange fluid temperature may drop below 0°C during circulation. The antifreeze properties of ethylene glycol ensure stable system operation even at -10°C.

[0072] The boiling point of a 40% ethylene glycol aqueous solution at atmospheric pressure is approximately 107°C, higher than pure water (100°C). This prevents the heat transfer fluid from boiling and generating bubbles during high-temperature conditions (such as during the heating phase), which could affect heat transfer efficiency. For example, during pressure compensation, a plate heat exchanger can raise the heat transfer fluid temperature to above 100°C to meet the wafer preheating temperature (150°C) required for subsequent CVD processes. The high boiling point of ethylene glycol ensures stable system operation even in high-temperature environments.

[0073] The specific heat capacity of a 40% ethylene glycol aqueous solution is approximately 3.8 kJ / (kg・K), which is lower than that of pure water (4.2 kJ / (kg・K)), but it offers superior fluidity. At the same flow rate, ethylene glycol's conductivity can meet wafer preheating requirements (for example, heating a 12-inch wafer from 25°C to 150°C requires approximately 1.2 kJ of heat, and at a heat exchange liquid flow rate of 10 L / min, the temperature drop is only 5°C). Furthermore, its low viscosity and high fluidity contribute to temperature uniformity on the preheating platform 41.

[0074] The waste heat temperature of a dry pump is usually 80°C-100°C. A 40% ethylene glycol aqueous solution will not decompose or deteriorate within this temperature range. After heat exchange, the temperature remains stable when it rises to 120°C. The heat exchange efficiency is maintained at above 85%, ensuring that the waste heat is effectively utilized.

[0075] Optionally, the plate heat exchanger is designed in counter-flow.

[0076] A counterflow design refers to a layout in which the primary side (dry pump waste heat) and the secondary side (heat exchange liquid) of a plate heat exchanger flow in opposite directions. Specifically, the primary side waste heat flows into the plate heat exchanger from one inlet, flows horizontally along the plate flow path, and reaches the other outlet. The secondary side heat exchange liquid flows in from the opposite inlet, creating a countercurrent flow with the waste heat.

[0077] In the co-current design, the outlet temperature of the cold fluid is always lower than the outlet temperature of the hot fluid, resulting in insufficient preheating capacity; while the counter-current design uses reverse flow to allow the heat exchange liquid to fully contact with the higher temperature waste heat at the outlet. Ultimately, the outlet temperature of the heat exchange liquid can exceed the outlet temperature of the waste heat, thereby meeting a wider range of temperature control requirements of the preheating platform 41.

[0078] Optionally, the cold source liquid storage tank is equipped with an air-cooled radiator.

[0079] Specifically, the air-cooled radiator adopts a fin-tube structure, which consists of a heat dissipation body, an axial-flow fan, a temperature sensor and a control module; the heat dissipation body includes finned tubes arranged in a U shape, and the temperature sensor is arranged on the outlet pipe of the cold source liquid storage tank. When it is detected that the temperature of the heat exchange liquid at the outlet is greater than the set value, the axial-flow fan is started.

[0080] More specifically, the air-cooled radiator is secured to the side of the cold source reservoir tank via an L-shaped bracket, 100 mm from the tank wall to facilitate air circulation. The cold source reservoir tank's outlet pipe is connected to the air-cooled radiator's inlet, which is then connected to the return flow port of the cold source reservoir tank via a bellows, forming a circulation branch from cold source reservoir tank to air-cooled radiator to cold source reservoir tank. The axial fan's power cable is connected in series with a PID temperature control module, and the module's signal cable is connected to the PID controller of the temperature control structure 50, enabling coordinated control.

[0081] When the temperature sensor detects that the heat exchange liquid in the cold source tank is higher than the set value, the overheated liquid flows out of the cold source tank (using a pump) and into the heat sink. As it flows through the finned tubes, the airflow generated by the axial fan passes horizontally across the fins, removing heat through forced convection. After the heat exchange liquid temperature drops to the target value, it returns to the cold source tank.

[0082] Adding an air-cooled radiator can prevent the heat exchange liquid from absorbing heat due to long-term circulation, causing the temperature to rise and affecting the viscosity and lubricity, ensuring that the heat exchange liquid remains in the optimal temperature range, thereby ensuring the temperature control efficiency of the wafer.

[0083] Optionally, a connecting pipe 43 is provided on the preheating platform 41; the supporting member 13 is a hollow structure, and a socket is provided on the bottom surface of the supporting member 13; after the preheating platform 41 is raised, the connecting pipe 43 can be inserted into the socket, and the heat source or cold source for temperature control can be input into the supporting member 13 through the connecting pipe 43, thereby controlling the temperature of the wafer through the supporting member 13.

[0084] If supplementary heat or cooling is required, an independent heat / cooling source supply device can be configured to specifically supply a heat source or cooling source (which can be liquid or gas) to the support member 13 through the connecting pipe 43 and the socket. Alternatively, the heat / cooling source (such as the heat exchange liquid mentioned above) can be provided by the temperature control structure 50. This application does not limit the specific type and source of the heat / cooling source.

[0085] For details, please refer to Figure 1 In the illustrated embodiment, the upper surface of the preheating platform 41 is provided with two sets of parallel grooves. Each set of grooves houses two vertically extending connecting pipes 43. One connecting pipe 43 in each groove is used to allow the heat / cold source to enter, while the other is used to allow the heat / cold source to exit. The portion of the support member 13 that contacts the wafer is designed in a finger-like shape. After the wafer is in place, the preheating platform 41 rises, and the support member 13 sinks into the groove, while the connecting pipes 43 are inserted into the support member 13.

[0086] To facilitate the insertion of connecting tube 43, a corresponding insertion hole is provided on the bottom surface of support member 13 facing preheating platform 41. When the wafer is in place, the insertion hole is directly opposite connecting tube 43. The matching tapered shape of connecting tube 43 and the insertion hole further facilitates the insertion of connecting tube 43 and prevents leakage.

[0087] Support member 13 is a hollow cavity with a serpentine flow channel inside. A receptacle on the bottom of support member 13 connects to the serpentine flow channel. When preheating platform 41 ascends, driven by lift driver 42, connecting pipe 43 is inserted into the receptacle, forming a sealed connection (an O-ring may be provided around the receptacle).

[0088] In one embodiment, preheating platform 41 is provided with a fluid channel, and support member 13 is a hollow cavity structure. After the wafer is in place, preheating platform 41 rises, contacting the wafer and enabling heat exchange with the wafer. Simultaneously, connecting pipe 43 on preheating platform 41 is inserted into support member 13, causing support member 13 to change temperature and also enabling heat exchange with the wafer. The preheating platform 41 and support member 13 work together to ensure that the wafer is fully heated and rapidly heated and cooled.

[0089] In another embodiment, no fluid channel is provided in the preheating platform 41. Through the liftable connecting pipe 43 (the preheating platform 41 and the connecting pipe 43 can be lifted or lowered together, or the connecting pipe 43 can be lifted or lowered independently), after the supporting member 13 carrying the wafer is in place, a heat source or a cold source is injected into the supporting member 13, and the wafer is preheated or precooled only through the supporting member 13.

[0090] In one embodiment, the electromagnetic docking wafer transfer device provided in the present application also includes: a nitrogen source, which can supply nitrogen to the support 13 through the connecting pipe 43, so that nitrogen can flow into and out of the support 13 as a heat exchange gas; a TEC semiconductor temperature control module, which is used to control the temperature of the nitrogen.

[0091] Using gas as a heat / cooling source prevents residual liquid within the support 13 from increasing in weight and affecting operational stability, or residual liquid from dripping into the cavity and causing contamination. Furthermore, nitrogen, as an inert gas, is chemically stable and does not react with oxide layers or metal wiring on the wafer surface at semiconductor process temperatures (-20°C to 300°C). This avoids contamination potentially caused by traditional air or other gases (such as oxygen-induced oxidation and etching defects caused by water vapor). Furthermore, the high speed of nitrogen molecules creates turbulence within the hollow flow channel of the support 13, thereby improving the heat transfer coefficient. Furthermore, combined with the TEC semiconductor temperature control module, it can achieve rapid temperature control at 10°C / s, making it suitable for processes such as etching and ion implantation that require rapid temperature increase / decrease.

[0092] Specifically, the TEC semiconductor temperature control module, based on the Peltier effect, consists of n-type and p-type semiconductor elements connected in series. When powered, one end absorbs heat (the cold end) and the other releases heat (the hot end). To cool the wafer, a nitrogen source (normally at 25°C) flows through a pipe through the TEC's cold end (-20°C), where it is cooled to the target temperature. It is then fed into the support 13 through a connecting pipe 43 to absorb heat from the wafer. To increase the temperature, the current flow through the TEC semiconductor temperature control module is reversed, turning the cold end into the hot end (150°C). The nitrogen flowing through the module is then heated to the desired temperature for wafer preheating.

[0093] The TEC semiconductor temperature control module has a short thermal response time and fast heating and cooling speeds. For example, after removing the wafer from process chamber 1 (300°C), the TEC-driven nitrogen can cool the wafer to 80°C within 40 seconds, thereby avoiding film stress cracking caused by prolonged high temperature.

[0094] Alternatively, the electromagnetic docking wafer transfer device provided by the present application further includes a nitrogen recovery and purification unit, which is connected to the support member 13 and the nitrogen source, and the nitrogen after heat exchange is returned to the nitrogen source through the nitrogen recovery and purification unit.

[0095] Specifically, the nitrogen recovery and purification unit includes the following connected in sequence: a buffer tank connected to the support member 13, through which the reflux nitrogen containing impurities enters the buffer tank and changes from a pulse flow to a steady flow; a first filter for intercepting impurity particles with a particle size greater than 0.5 μm; a condensation dehumidifier for condensing water vapor in the nitrogen; a second filter using a PTFE membrane filter for intercepting impurity particles with a particle size of 0.1-0.5 μm and capable of blocking residual oil vapor through a hydrophobic membrane; and a molecular sieve adsorption tower for adsorbing residual water molecules and organic gases in the nitrogen.

[0096] The nitrogen recovery and purification unit forms a closed loop with the support member 13 and the nitrogen source through a pipeline. Among them, the buffer tank is used for pressure stabilization. The reflux nitrogen discharged from the support member 13 may form turbulence due to the pulsed flow during the temperature control process. After entering the buffer tank, the flow rate decreases. The buffer tank can also eliminate pressure fluctuations by expanding the flow cross-sectional area, converting the pulse flow into a stable flow. The buffer tank uses the "volume buffer effect" to reduce the pressure fluctuation amplitude from ±0.1MPa to ±0.01MPa, providing a uniform gas source for subsequent filtration and avoiding damage to the filter material of the downstream filter due to the pulse flow.

[0097] The nitrogen recovery and purification unit provided in this application removes impurities through two-stage filtration. The first filter (using a metal sintered mesh with a pore size of 0.5 μm) can intercept large impurities such as dust and metal debris; the second filter (using a PTFE membrane with a pore size of 0.1 μm) can further remove submicron particles.

[0098] Unpurified nitrogen may contain oil vapor (originating from dry pump lubrication systems, vacuum sealant, and pipeline residue). If it enters transfer chamber 20 or process chamber 1 directly, it can cause photoresist contamination. The PTFE membrane possesses superoleophobic properties, intercepting oil vapor by condensing into droplets upon contact with the membrane surface. Furthermore, the PTFE membrane's nanoscale pores can capture oil mist sized 0.03-0.1μm, effectively blocking oil vapor and ensuring the oil content of the nitrogen is below 0.1ppm.

[0099] Unpurified nitrogen may also contain water vapor (from the nitrogen itself, wafer release, and environmental infiltration). If it enters the transfer chamber 20 or process chamber 1 directly, it will form a water film on the wafer surface, causing thin film defects in processes such as CVD. A condensing dehumidifier uses the principle of compression refrigeration. The refrigerant absorbs heat in the evaporator, lowering the nitrogen temperature below the dew point. The water vapor in the nitrogen condenses and is then discharged through the gas-liquid separator.

[0100] The nitrogen after filtration and drainage enters the molecular sieve adsorption tower, where residual water molecules and organic gases (such as photoresist volatiles) are removed through physical adsorption to ensure the purity of the nitrogen.

[0101] In traditional solutions, nitrogen gas after heat exchange is directly discharged after a single use. Using a nitrogen recovery and purification unit to purify and recycle nitrogen can increase nitrogen recycling efficiency and save costs.

[0102] Optionally, differential pressure sensors are installed at both ends of the inlet and outlet of the first filter and / or the second filter.

[0103] The differential pressure sensor is rigidly connected to the filter body via a flange and monitors the pressure differential across the filter media in real time. When trapped particles in the filter cause the differential pressure to exceed the set value, the sensor transmits an electrical signal to the control system, triggering an audible and visual alarm. This simultaneously activates a bypass solenoid valve, allowing nitrogen to bypass the filter and flow directly downstream (either to discharge or to a nitrogen source), preventing sudden increases in system pressure due to filter media clogging.

[0104] Optionally, the molecular sieve adsorption tower is arranged in a dual-tower parallel form and has a thermal regeneration function.

[0105] Specifically, the nitrogen recovery and purification unit provided in the present application includes two molecular sieve adsorption towers (hereinafter referred to as Tower 1 and Tower 2). The two molecular sieve adsorption towers are connected in parallel through pipelines and valve groups to form a closed-loop system that alternates between "adsorption and regeneration".

[0106] In one specific embodiment, both towers one and two are filled with 13X molecular sieve. The towers are connected by a pipeline and equipped with a pneumatic switching valve and pressure sensor. During operation, the inlet valve of tower one is open, allowing impurity-laden nitrogen to enter from the bottom of the tower. After adsorption by the molecular sieve, it is discharged from the top of the tower and returned to the nitrogen source. During this process, tower two is in a regeneration state, and the inlet valve is closed. When the outlet dew point of tower one exceeds a set value (measured by an online dew point meter) or the operating time reaches a preset value, the control system triggers a switch, closing the inlet valve of tower one and opening the inlet valve of tower two, switching nitrogen flow to tower two. In this way, while one molecular sieve adsorption tower is in operation, the other is in a regeneration state. Compared to a single-tower design that requires shutdown for regeneration, the dual-tower design provides uninterrupted gas supply around the clock, helping to improve equipment efficiency. Furthermore, if one molecular sieve adsorption tower fails, the other can continue to operate independently, thus avoiding production line downtime due to gas supply interruption.

[0107] When the molecular sieve adsorption tower enters the regeneration state, 150°C hot nitrogen is introduced into the tower, heating the saturated molecular sieve and desorbing the adsorbed water and organic gases, ultimately achieving thermal regeneration. For example, after a tower switches to the regeneration state, the hot nitrogen inlet valve opens, and 150°C hot nitrogen is introduced from the top of the tower. At this time, the hot nitrogen flow direction is opposite to the airflow direction during the adsorption phase (reverse regeneration), which lasts for 2 hours. The regeneration waste gas (containing desorbed water vapor and organic matter) is treated in a condensing dehumidifier and then discharged. After regeneration is complete, the tower naturally cools to below 40°C and waits for the next switch.

[0108] Optionally, a chilled mirror dew point meter is provided in the outlet pipe of the molecular sieve adsorption tower, and the sensing probe thereof is coaxially arranged with the nitrogen main flow channel, so as to monitor the dew point value of the purified nitrogen in real time.

[0109] When the dew point exceeds a set value (e.g., -60°C, representing a water vapor content greater than 1 ppm), the dew point meter automatically triggers a dual-tower switchover process via a signal-linked control system. For example, during adsorption operation, the inlet and outlet valves of the first tower are closed, while the standby second tower is opened. The second tower continues adsorption operation while the first tower begins regeneration at 150°C with hot nitrogen.

[0110] Dew point detection can ensure the efficient and normal operation of the molecular sieve adsorption tower, avoid water film defects on the wafer surface caused by residual water vapor, and ensure the stable operation of the semiconductor process.

[0111] Optionally, the nitrogen source adopts a nitrogen storage tank, and a spring-loaded safety valve is vertically installed on the top of the nitrogen storage tank, and the valve disc opening pressure is set to 1.2MPa (4 times the safety factor higher than the working pressure of 0.3MPa).

[0112] When the pressure in the nitrogen storage tank exceeds the threshold due to an abnormality (such as gas compression caused by a condenser dehumidifier failure), the valve flap automatically opens to release the pressure, thereby ensuring that the pressure in the tank does not exceed 110% of the design value.

[0113] Furthermore, flow sensors and overcurrent protection solenoid valves are provided on the inlet and outlet pipes of the nitrogen storage tank, and the outer wall of the nitrogen storage tank is also covered with an explosion-proof film.

[0114] When the flow sensor detects an abnormal surge in nitrogen flow (e.g., due to a pipeline rupture), the overcurrent protection solenoid valve immediately closes, blocking the flow. This, combined with the explosion-proof membrane on the nitrogen tank's outer wall, provides triple protection, reducing the risk of explosion. Overcurrent protection also prevents nitrogen leaks from causing a drop in oxygen concentration in the workshop, thereby ensuring operator safety.

[0115] Optionally, the electromagnetic docking wafer transfer device provided in the present application also includes a first detection component 51, which is arranged in the transfer chamber 20 and is used to detect whether the wafer has reached the top of the preheating platform 41; after the wafer is in place, the lifting drive component 42 drives the preheating platform 41 to rise so that the wafer can be preheated using the temperature control structure 50. At the same time, the second electromagnet is powered off and the first slide rail 12 exits the transfer chamber 20.

[0116] In a specific embodiment, the first detection component 51 adopts a through-beam photoelectric sensor, which consists of a transmitter and a receiver; the transmitter and the receiver are respectively installed on both sides of the inner wall of the transfer chamber 20 in the width direction, 50 mm above the preheating platform 41; the optical axes of the transmitter and the receiver are aligned with the movement path of the support component 13 carrying the wafer. During operation, the transmitter continuously emits an infrared beam, and the receiver monitors in real time whether the beam is blocked. When the support component 13 carries the wafer and moves along the second slide rail 31 to the top of the preheating platform 41, the wafer blocks the beam, the signal strength of the receiver drops sharply, and the sensor is triggered to output a high-level signal. The sensor signal is connected to the control system, triggering the following actions:

[0117] The lifting drive member 42 is activated to raise the preheating platform 41, so that the supporting member 13 falls into the groove;

[0118] The temperature control structure 50 works so that the preheating platform 41 and the wafer can exchange heat;

[0119] The second electromagnet is powered off, and the first slide rail 12 is driven by the first driving member 11 to exit the transfer chamber 20;

[0120] Subsequently, the first gate valve 21 is closed (the second gate valve 22 is also in a closed state), and the dry pump is started.

[0121] The addition of the first detection component 51 can solve the problems of "insufficient position detection accuracy" and "asynchronous action timing" in semiconductor wafer transmission. Its high reliability design ensures the stability of the entire line operation, and is particularly suitable for mass production scenarios that are sensitive to beat time.

[0122] Optionally, the electromagnetic docking wafer conveying device provided in the present application also includes a second detection member 52, which is used to detect whether the first slide rail 12 enters or leaves the transfer chamber 20; after the first slide rail 12 carries the support member 13 and the wafer into the transfer chamber 20, the second electromagnet is energized to facilitate the rapid docking of the two sets of rails; after the first slide rail 12 leaves the transfer chamber 20, the first gate valve 21 is closed and the dry pump is started.

[0123] In one specific embodiment, the second detection element 52 is a high-frequency oscillating proximity sensor consisting of a detection head, a stainless steel housing, and a high-temperature-resistant cable. The detection head is mounted on the sidewall at the entrance of the transfer chamber 20 (i.e., near the location of the first gate valve 21), with its detection surface perpendicular to the end face of the first slide rail 12. The sensor's internal LC oscillating circuit generates a high-frequency electromagnetic field. When the first slide rail 12 enters the detection range, eddy currents are generated on the rail's metal surface, causing the oscillation amplitude to decay and the sensor to output a high-level signal. When the rail leaves the detection range, the oscillation resumes, and the sensor outputs a low-level signal.

[0124] The second detection member 52 detects that the first slide rail 12 has entered the transfer chamber 20, and transmits a signal to the control system, triggering the following actions:

[0125] The second electromagnet is energized to quickly connect the first slide rail 12 with the second slide rail 31;

[0126] The first driving member 11 decelerates to ensure that the slide rail is in place smoothly.

[0127] The second detection member 52 detects that the first slide rail 12 has left the transfer chamber 20, and transmits a signal to the control system, triggering the following actions:

[0128] The first gate valve 21 is closed, and the transfer chamber 20 enters a sealed state;

[0129] The dry pump is started to pump the pressure of the transfer chamber 20 from atmospheric pressure to the target value.

[0130] The addition of the second detection component 52 can solve the problems of "track docking timing asynchrony" and "poor adaptability to the vacuum environment" in semiconductor wafer transmission. Its high reliability design ensures the stability of the entire line's automated operation, and is especially suitable for advanced process equipment with strict requirements on transmission accuracy and vacuum degree.

[0131] Optionally, the electromagnetic docking wafer conveying device provided in the present application also includes a third driving member 61, which is used to drive the first driving member 11 and the first slide rail 12 to move between at least two workstations; after the first driving member 11 and the first slide rail 12 send a group of supporting members 13 into a transfer chamber 20, the first slide rail 12 withdraws and is dispatched by the third driving member 61 to another transfer chamber 20 to perform the transfer task.

[0132] The third driving member 61 can adopt a driving structure such as an electric cylinder or a linear module.

[0133] In a specific embodiment, referring to Figure 4 The electromagnetic docking wafer transfer device is equipped with two groups of transfer chambers 20 and two groups of supporting members 13. Each group of transfer chambers 20 is docked with an independent process chamber 1. The first driving member 11 can carry the first slide rail 12 back and forth between the two transfer chambers 20 under the drive of the third driving member 61. During operation, one group of supporting members 13 carries the wafer into a transfer chamber 20, and after preheating and vacuuming, the first driving member 11 and the first slide rail 12 exiting the transfer chamber 20 can be driven by the third driving member 61 to go to another transfer chamber 20, so that the first slide rail 12 docks with another second slide rail 31 to take out the wafer that has completed the process; after the supporting member 13 receives the new wafer to be processed, the first driving member 11 and the first slide rail 12 can send the group of supporting members 13 and the wafer into the idle transfer chamber 20.

[0134] Traditional single-station transfer requires waiting for the previous wafer to complete processing before transferring, resulting in a low UPH (wafers processed per hour). The addition of the third drive 61 prevents the first drive 11 and first slide 12 from being idle. These two devices enable dual-station alternating operation, helping to improve UPH and increase production capacity.

[0135] After transfer chamber 20 is evacuated and the wafers are pre-cooled or pre-heated, second driver 32 drives support 13 to transfer the wafers into process chamber 1. Support 13 then returns to transfer chamber 20, and second gate valve 22 closes. While the wafers are being processed, support 13 and transfer chamber 20 remain idle.

[0136] To fully utilize the equipment's idle time, in one embodiment, wafers are preheated on preheating platform 41 before entering process chamber 1. After completing the process, the wafers return to transfer chamber 20 where they are cooled by preheating platform 41. In this embodiment, while the wafers are undergoing processing, support member 13 returns to transfer chamber 20 and onto preheating platform 41. After preheating platform 41 is raised, support member 13, preheating platform 41, and transfer chamber 20 are precooled via temperature control structure 50 and / or connecting pipe 43. This accelerates subsequent cooling of the wafers.

[0137] Optionally, the electromagnetic docking wafer transfer device provided herein also includes a laser calibration system. This system consists of three laser displacement sensors mounted on the inner wall of the transfer chamber 20. These three laser displacement sensors correspond to the three orthogonal directions (X, Y, and Z), respectively. The laser beams emitted by these sensors can be projected perpendicularly onto the detection surfaces of the first and second rails 12 and 31. When the support member 13 enters the transfer chamber 20 along with the first rail 12, the three laser displacement sensors scan the surface profiles of the first and second rails 12 and 31 in real time. Using triangulation, they calculate the positional deviations (e.g., horizontal offset, pitch angle, and yaw angle) between the first and second rails 12 and 31, and synchronously transmit this data to the control system. The control system automatically generates compensation parameters and drives the third drive member 61 to fine-tune the position of the first rail 12, thereby reducing rail docking errors and ensuring that the support member 13 always precisely fits into the grooves on the preheating platform 41. This mechanism can correct for rail wear deviations caused by long-term operation in real time, improving and ensuring the positioning accuracy of wafer transfer.

[0138] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. An electromagnetic docking wafer conveying device, characterized in that: include: a first driving member and a first slide rail, wherein the first driving member is used to drive the first slide rail to move; A transfer chamber, wherein one end of the transfer chamber is provided with a first gate valve that can be opened and closed, and the other end is provided with a second gate valve that can be opened and closed, the first gate valve faces the first slide rail, and the second gate valve is connected to the process chamber; a dry pump, used for evacuating the transfer chamber; a second slide rail, disposed in the transfer cavity and adapted to dock with the first slide rail; a supporting member, used for carrying the wafer and capable of moving along the first slide rail and the second slide rail; a second driving member, disposed in the transfer cavity, for driving the supporting member to move; a first electromagnet, disposed on the first slide rail, capable of attracting and fixing the supporting member when energized; a second electromagnet, disposed at the butt end of the first slide rail or the second slide rail, capable of adsorbing and fixing the first slide rail and the second slide rail when energized so that the two are closely aligned; a third electromagnet, provided on the second driving member, capable of attracting the supporting member to switch the driving body when energized; During operation, the first electromagnet is in an energized state, fixing the supporting member on the first slide rail. After the supporting member receives the wafer to be processed, the first driving member drives the first slide rail to carry the supporting member and the wafer through the first gate valve into the transfer chamber. The second electromagnet is energized to achieve precise docking of the first slide rail and the second slide rail; The third electromagnet is energized to attract the supporting member, the first electromagnet is de-energized to release the supporting member, and the second driving member drives the supporting member to move from the first slide rail to the second slide rail; The first driving member drives the first slide rail to withdraw from the transfer cavity; After the first gate valve and the second gate valve are both in the closed state, the dry pump can evacuate the transfer chamber to facilitate regulating the air pressure in the transfer chamber to make it close to the working pressure of the process chamber; After the pressure relief is completed, the second driving member can drive the supporting member to carry the wafer into the process chamber through the second gate valve.

2. The electromagnetic docking wafer transfer device according to claim 1, characterized in that: The second electromagnet includes a coaxially arranged fixed iron core and a movable iron core, the fixed iron core is arranged at the butt end of the first slide rail or the second slide rail, and the movable iron core is elastically connected to the center hole of the fixed iron core through a spring; The end of the movable iron core is provided with a conical positioning head; A conical groove adapted to the conical positioning head is provided on the rail butt end opposite to the movable iron core; When power is turned on, the movable iron core overcomes the spring force under the action of magnetic force and moves toward the conical groove, and the conical positioning head is inserted into the conical groove to realize automatic centering of the two sets of rails. At the same time, the fixed iron core is tightly adsorbed to the docking end of the rail to form a rigid connection.

3. The electromagnetic docking wafer transfer device according to claim 1, characterized in that: The first electromagnet and the third electromagnet both adopt a bipolar electromagnetic structure, including alternating N-pole coils and S-pole coils, and the supporting member is correspondingly provided with an alternating permanent magnet array matching the bipolar electromagnetic structure; When the first electromagnet or the third electromagnet is energized, the direction of the current is controlled so that the adjacent coils generate magnetic fields in opposite directions, forming a magnetic locking effect with the permanent magnet array, so as to achieve horizontal positioning constraint while adsorbing the supporting member.

4. The electromagnetic docking wafer transfer device according to claim 1, characterized in that: Also includes: a preheating platform, the preheating platform being disposed in the transfer chamber and located on one side of the second slide rail; A lifting drive member, used for driving the preheating platform to perform lifting motion; After the second driving member drives the supporting member to move along the second slide rail with the wafer to above the preheating platform, the lifting driving member drives the preheating platform to rise, and the preheating platform is able to support the supporting member; The preheating platform is provided with a groove that matches the shape of the supporting member; After the preheating platform is raised, the supporting member can be sunk into the groove so that the preheating platform can contact the wafer; The preheating platform is equipped with a temperature control structure, which can preheat or precool the wafer so that the temperature of the wafer is close to the process temperature, thereby improving the subsequent processing efficiency.

5. The electromagnetic docking wafer conveying device according to claim 4, characterized in that: The temperature control structure includes: Cold source liquid storage tank, used to store heat exchange liquid; A plate heat exchanger, wherein the primary side inlet of the plate heat exchanger is connected to the dry pump, and the secondary side inlet is connected to the cold source liquid storage tank; A variable frequency circulation pump connected to the cold source liquid storage tank and the plate heat exchanger; A temperature detector, used to monitor the temperature of the preheating platform; A PID temperature control module, connected to the temperature detector and the variable frequency circulation pump, capable of dynamically adjusting the pump flow rate and heat exchange duration according to the detection results of the temperature detector, so as to maintain the temperature of the preheating platform at a set value; The dry pump works to generate waste heat, and the variable frequency circulation pump pumps the heat exchange liquid into the secondary side of the plate heat exchanger. The waste heat enters the primary side of the plate heat exchanger, causing the heat exchange liquid to absorb heat and increase in temperature. A fluid channel is provided in the preheating platform, and the heated heat exchange liquid enters the fluid channel to indirectly control the temperature of the wafer; The heat exchange liquid after heat exchange flows back to the cold source liquid storage tank.

6. The electromagnetic docking wafer transfer device according to claim 4, characterized in that: The preheating platform is provided with a connecting pipe; The supporting member is a hollow structure, and a socket is provided on the bottom surface of the supporting member; After the preheating platform is raised, the connecting pipe can be inserted into the socket, and the heat source or cold source for temperature control can be input into the supporting member through the connecting pipe, thereby controlling the temperature of the wafer through the supporting member.

7. The electromagnetic docking wafer conveying device according to claim 6, characterized in that: Also includes: a nitrogen source capable of supplying nitrogen to the supporting member through the connecting pipe; TEC semiconductor temperature control module, used to control the temperature of nitrogen; A nitrogen recovery and purification unit is connected to the support member and the nitrogen source, and the nitrogen after heat exchange is returned to the nitrogen source through the nitrogen recovery and purification unit; the nitrogen recovery and purification unit includes: A buffer tank is connected to the support member, and the reflux nitrogen containing impurities enters the buffer tank and changes from a pulse flow to a steady flow; The first filter is used to intercept impurity particles with a particle size greater than 0.5 μm; Condensation dehumidifier, used to condense water vapor in nitrogen; The second filter uses a PTFE membrane filter to intercept impurity particles with a particle size of 0.1-0.5μm and can block residual oil vapor through the hydrophobic membrane; Molecular sieve adsorption tower is used to adsorb residual water molecules and organic gases in nitrogen.

8. The electromagnetic docking wafer conveying device according to claim 4, characterized in that: It also includes a first detection component, which is arranged in the transfer chamber and is used to detect whether the wafer reaches the top of the preheating platform; After the wafer is in place, the lifting drive component drives the preheating platform to rise so that the temperature control structure can preheat the wafer. At the same time, the second electromagnet is powered off and the first slide rail exits the transfer chamber.

9. The electromagnetic docking wafer transfer device according to claim 1, characterized in that: Also included is a second detection member, the second detection member being used to detect whether the first slide rail enters or leaves the transfer cavity; After the first slide rail carries the supporting member and the wafer into the transfer chamber, the second electromagnet is energized to facilitate rapid docking of the two sets of rails; After the first slide rail leaves the transfer chamber, the first gate valve is closed and the dry pump is started.

10. The electromagnetic docking wafer transfer device according to any one of claims 1 to 9, characterized in that: Also included is a third driving member, the third driving member being used to drive the first driving member and the first slide rail to move between at least two workstations; After the first driving member and the first slide rail send a group of the supporting members into one transfer cavity, the first slide rail withdraws and is dispatched by the third driving member to another transfer cavity to perform the transfer task.

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