Workpiece table for proximity contact exposure machine

Abstract

The application discloses a workpiece table of a proximity contact exposure machine, a horizontal driving device has freedom degrees of movement along an X-axis direction and a Y-axis direction; a rotating table has a freedom degree of rotation around a central axis thereof; a lifting table is arranged above the rotating table and has a freedom degree of movement along a Z-axis direction; a Z-axis voice coil motor is arranged between the rotating table and the lifting table and is used for driving the lifting table to move along the Z-axis direction; a ball bowl leveling assembly is arranged between a wafer table and the lifting table and comprises a ball bowl seat with a bowl cavity and a ball head matched with the bowl cavity; a recess cavity is arranged at the bottom of the bowl cavity; the spherical surface of the ball head is in sliding sealing cooperation with the spherical inner wall surface of the bowl cavity and seals the recess cavity; and a mask frame is arranged above the wafer table. The application can adjust the relative position and posture between a mask plate and a wafer, accurately control the leveling process, effectively realize high-precision movement of four degrees of freedom and accurate control of the leveling contact force, and has high practicability. Z four degrees of freedom

Description

Technical Field

[0001] This invention relates to the field of photolithography technology, and in particular to a workpiece stage for a proximity contact exposure machine. Background Technology

[0002] Proximity contact lithography refers to a process where a tiny gap (approximately 0–200 μm) is maintained between the photomask and the photoresist substrate. This effectively avoids damage to the photomask caused by direct contact with the photoresist, resulting in a more durable mask and photoresist substrate, longer mask lifespan (up to 10 times), and fewer pattern defects. Proximity contact lithography is the most widely used technique in modern photolithography processes.

[0003] Proximity mask exposure requires precise adjustment of the relative position (the mask and the markings on the wafer overlap in the projection direction) and orientation (the mask and the wafer are parallel) between the mask and the wafer to ensure a uniform exposure gap, thereby guaranteeing better exposure results. R... X With R Y Leveling is achieved through mechanical contact by inserting three equal-diameter leveling spheres arranged in an equilateral triangle between the mask and the wafer, ensuring the parallelism between the mask and the wafer; the X / Y / Z relative positions and R... Z Orientation and attitude adjustment mainly rely on high-precision X / Y / Z / R. Z This is achieved through high-precision motion with four degrees of freedom. The two most critical requirements in the entire leveling and alignment process are: a. During leveling, the contact force between the leveling ball and the wafer should be minimized to prevent the leveling ball from sticking to the photoresist applied to the wafer; b. During alignment, high precision and speed should be ensured to guarantee the performance and yield of the exposed products.

[0004] Chinese invention patent application number 202210842328.2 discloses a rotary lifting alignment device based on ball splines. It uses a stepper motor combined with a ball screw to achieve X / Y / R... Z The motion has three degrees of freedom. In the Z-axis, a servo motor combined with a ball spline structure is used to achieve precise Z-axis motion and thrust control for leveling. Due to the X / Y / Z / R... ZThe motion in all four degrees of freedom incorporates mechanical transmission structures. On one hand, the machining precision of these mechanical transmission structures is far lower than the required motion precision (by approximately an order of magnitude). The introduction of mechanical transmission cannot directly guarantee the required motion precision; a linear encoder must be added at the actuator end for feedback to achieve high-precision control. The inherent deformation and clearance of the mechanical transmission structure itself place higher demands on control and reduce alignment speed (requiring more alignment attempts to achieve accurate alignment in the same single alignment time). On the other hand, since the Z-axis thrust during leveling relies on servo motor current feedback to control the contact force, the unstable friction within the mechanical transmission structure poses a greater challenge to controlling the leveling contact force, making precise control of the contact force impossible. Summary of the Invention

[0005] To address the aforementioned technical problems, the objective of this invention is to provide a workpiece stage for a near-contact exposure machine, capable of adjusting the relative position and orientation between the mask and the wafer, and achieving precise control of the leveling process, effectively realizing X / Y / Z / R... Z It features high-precision motion with four degrees of freedom and precise control of leveling contact force, making it highly practical.

[0006] The technical solution of the present invention is implemented as follows: a workpiece stage of a proximity contact exposure machine, comprising a horizontal drive mechanism, a rotary table, a lifting table, a wafer stage, a Z-axis voice coil motor, a mask holder, a vacuum device, a rotary drive mechanism, and a ball cup leveling assembly.

[0007] The horizontal drive device has degrees of freedom to move along the X-axis and Y-axis directions;

[0008] The rotary table is mounted on a horizontal drive device and has the degree of freedom to rotate around its own central axis; the central axis of the rotary table extends along the Z-axis direction.

[0009] The rotary drive mechanism is mounted on the horizontal drive device and is used to drive the rotary table to rotate around its own central axis.

[0010] The lifting platform is positioned above the rotary table and has a degree of freedom to move along the Z-axis.

[0011] The Z-axis voice coil motor is located between the rotary table and the lifting table, and is used to drive the lifting table to move along the Z-axis direction;

[0012] The wafer stage is positioned above the lifting platform;

[0013] The ball-and-socket leveling assembly is disposed between the wafer stage and the lifting stage, and includes a ball-and-socket seat with a bowl-shaped cavity and a ball head adapted to the bowl-shaped cavity; the bottom of the bowl-shaped cavity is provided with a concave cavity; the spherical surface of the ball head slides and seals with the spherical inner wall surface of the bowl-shaped cavity to close the concave cavity; the ball-and-socket seat is disposed on one of the wafer stage and the lifting stage, and the ball head is disposed on the other.

[0014] The vacuum pumping device is connected to the cavity and is used to evacuate the cavity.

[0015] The mask holder is positioned above the wafer stage, and a mask is provided on the mask holder corresponding to the wafer stage.

[0016] Furthermore, the horizontal drive device includes an X-axis drive device and a Y-axis drive device; the X-axis drive device includes an X-axis carrier plate and an X-axis voice coil motor for driving the X-axis carrier plate to move along the X-axis direction; the Y-axis drive device includes a Y-axis carrier plate movably disposed on the X-axis carrier plate and a Y-axis voice coil motor disposed on the X-axis carrier plate for driving the Y-axis carrier plate to move along the Y-axis direction; the rotary table is disposed on the X-axis carrier plate or the Y-axis carrier plate.

[0017] Furthermore, the rotary drive mechanism includes a rotary arm and R. Z Shaft voice coil motor, transmission assembly; the R Z The shaft voice coil motor is mounted on a horizontal drive unit and is connected to the rotary table via a transmission assembly to drive the rotary table to rotate around its own central axis.

[0018] Furthermore, the transmission assembly includes a rotating arm and a bearing; the rotating arm has a first end connected to the rotary table and a second end away from the first end; the bearing is disposed at the second end of the rotating arm and rotates about its own central axis; the central axis of the bearing extends along the Z-axis direction; the R... Z The shaft voice coil motor has a drive end that moves in a horizontal linear direction; the R Z A limiting space is provided on the drive end of the shaft voice coil motor; the bearing is accommodated in the limiting space and is restricted by the limiting space to R. Z The shaft voice coil motor moves in the driving direction.

[0019] Furthermore, the limiting space has a range of R Z Two limiting sidewalls are arranged opposite each other in the driving direction of the shaft voice coil motor; the outer peripheral surface of the bearing is in contact with the two limiting sidewalls respectively.

[0020] Furthermore, the workpiece stage includes a gravity-bearing cylinder; the gravity-bearing cylinder is mounted on a horizontal drive device and has a bearing position in which its drive end extends below the lifting platform and bears the lifting platform, and a yielding position in which its drive end avoids the movement of the lifting platform.

[0021] Furthermore, the workpiece stage includes a load balancing cylinder; the load balancing cylinder is connected between the rotary table and the lifting table.

[0022] Furthermore, the workpiece stage includes a leveling ball transmission mechanism; the leveling ball transmission mechanism includes a bracket, a plurality of leveling balls disposed on the bracket, a first driver connected to the bracket for driving the bracket to rise and fall, and a second driver for driving the first driver to move horizontally; the bracket has a position for moving under the drive of the second driver to a mating position between the wafer stage and the mask, and a clearance position away from the wafer stage; the diameter of each leveling ball is the same.

[0023] Furthermore, there are three leveling balls, distributed at the three corner points of the equilateral triangle.

[0024] Furthermore, the workpiece stage includes a first grating ruler for detecting the position of the horizontal drive device in the X-axis direction, a second grating ruler for detecting the position of the horizontal drive device in the Y-axis direction, a third grating ruler for detecting the rotational position of the rotary table, and a fourth grating ruler for detecting the position of the lifting table in the Z-axis direction.

[0025] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0026] 1. This invention utilizes a Z-axis voice coil motor to drive the lifting platform's movement. The thrust is directly estimated (almost proportionally) through the Z-axis voice coil motor's current, forming force feedback control. This effectively controls the thrust applied to the lifting platform, achieving leveling with minimal leveling contact force and preventing the leveling balls from adhering to the photoresist on the wafer. Furthermore, it replaces conventional mechanical transmission structures, avoiding the complex and time-varying friction forces inherent in mechanical transmissions. Only relatively stable guide rail friction exists, effectively achieving high-precision movement of the lifting platform in the Z-axis direction and precise control of the leveling contact force, making it highly practical.

[0027] 2. This invention, through the combined use of an X-axis voice coil motor and a Y-axis voice coil motor, can adjust the position of the rotary table and related components on the rotary table in the X and Y axes. The movement in the X and Y axes is directly driven by the X-axis and Y-axis voice coil motors. High-precision first and second grating rulers are used for feedback to achieve high-precision movement in the X and Y axes. Furthermore, the X-axis and Y-axis voice coil motors are arranged as close as possible to the middle of the X-axis and Y-axis carrier plates, resulting in smaller offset torque, less structural deformation, and strong practicality.

[0028] 3. This invention utilizes R Z The combined use of a shaft voice coil motor and transmission components, R ZA shaft voice coil motor can drive the rotating arm to swing, which in turn drives the rotary table to rotate, thereby adjusting the wafer stage in the R direction. Z Position in the direction, and through R Z A high-precision grating ruler is used to generate feedback in the shaft voice coil motor to achieve R Z High-precision directional movement with strong practicality.

[0029] 4. This invention, through the combined use of the ball-shaped cup and the ball-shaped head, enables the wafer stage to be positioned in R... X With R Y The wafer stage can rotate freely within a small range in the directional direction. When the wafer stage, leveling ball, and mask come into contact, it can automatically correct the orientation of the wafer stage to make it parallel to the mask. A vacuum is created by drawing a vacuum to form a vacuum adsorption and fixation between the ball holder and the ball head, thereby positioning and fixing the wafer stage and the lifting platform to maintain the parallelism of the wafer stage. The combination of these methods enables precise control of the contact force during the leveling process, resulting in high leveling accuracy, a fast and stable leveling process, and effectively meeting actual production needs. Attached Figure Description

[0030] The technical solution of the present invention will be further described below with reference to the accompanying drawings:

[0031] Figure 1 This is a three-dimensional structural diagram of the overall structure of the present invention;

[0032] Figure 2 for Figure 1 A side view structural diagram;

[0033] Figure 3 This is a three-dimensional structural diagram of the horizontal drive device and the rotary table of the present invention;

[0034] Figure 4 for Figure 3 A three-dimensional structural diagram from another perspective;

[0035] Figure 5 for Figure 3 A three-dimensional structural diagram from another perspective;

[0036] Figure 6 This is a three-dimensional structural schematic diagram of the rotary drive mechanism and rotary table of the present invention;

[0037] Figure 7 for Figure 6 A side view structural diagram;

[0038] Figure 8 This is a three-dimensional structural schematic diagram of the leveling ball transmission mechanism of the present invention;

[0039] Figure 9This is a cross-sectional view of the wafer stage, lifting seat, and ball cup leveling assembly of the present invention.

[0040] Figure 10 This is a three-dimensional structural schematic diagram of the ball-shaped cup holder of the present invention;

[0041] Figure 11 This is a three-dimensional structural diagram of the ball head of the present invention;

[0042] The components include: 1. Base; 11. Mask holder; 12. Support side plate; 2. Horizontal drive device; 21. X-axis carrier plate; 211. X-axis voice coil motor; 212. First grating ruler; 22. Y-axis carrier plate; 221. Y-axis voice coil motor; 222. Second grating ruler; 3. Rotary stage; 31. R Z 32. Rotating arm; 33. Bearing; 34. Limiting component; 35. Limiting space; 4. Z-axis voice coil motor; 41. Load balancing cylinder; 42. Lifting slider; 421. Fourth grating ruler; 43. Gravity bearing cylinder; 5. Lifting platform; 6. Wafer stage; 7. Ball cup leveling assembly; 71. Ball cup seat; 711. Bowl-shaped cavity; 712. Concave cavity; 72. Ball head; 8. Leveling transmission mechanism; 81. Bracket; 82. Leveling ball; 83. First driver; 84. Sliding seat; 85. Second driver; 9. Vacuum pumping device. Detailed Implementation

[0043] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0044] like Figure 1-11The workpiece stage of a proximity contact exposure machine described in this embodiment includes a base 1, a horizontal drive mechanism, a rotary table 3, a lifting table 5, a wafer stage 6, a Z-axis voice coil motor 4, a mask holder 11, a vacuum device 9, a rotary drive mechanism, and a ball-and-socket leveling assembly 7. The horizontal drive device 2 is mounted on the base 1. The horizontal drive device 2 has degrees of freedom of movement along the X-axis and Y-axis directions. Specifically, the horizontal drive device 2 includes an X-axis drive device and a Y-axis drive device. The X-axis drive device includes an X-axis carrier plate 21 and an X-axis voice coil motor 211. The X-axis carrier plate 21 is mounted on the base 1 via a guide rail slider mechanism, enabling movement along the X-axis. The X-axis voice coil motor 211 is fixed to the base 1, and its drive end is connected to the X-axis carrier plate 21 to drive the X-axis carrier plate 21 to move along the X-axis. The aforementioned Y-axis drive device includes a Y-axis carrier plate 22 and a Y-axis voice coil motor 221. The Y-axis carrier plate 22 is mounted on the X-axis carrier plate 21 via a guide rail slider mechanism, enabling it to move along the Y-axis direction. The aforementioned Y-axis voice coil motor 221 is fixed to the X-axis carrier plate 21, and its drive end is fixedly connected to the Y-axis carrier plate 22 to drive the Y-axis carrier plate 22 to move along the Y-axis direction.

[0045] In the specific structural design, the X-axis voice coil motor 211 is arranged as close as possible to the middle of the X-axis carrier plate 21, and the Y-axis voice coil motor 221 is arranged as close as possible to the middle of the Y-axis carrier plate 22, so as to reduce the torsional torque on their respective guide rails when offset.

[0046] The aforementioned rotary table 3 is mounted on the Y-axis carrier plate 22 of the horizontal drive device 2 via bearings 33, thus possessing the degree of freedom to rotate about its own central axis. The central axis of the rotary table 3 is defined as extending along the Z-axis direction. In this embodiment, the X-axis, Y-axis, and Z-axis are mutually perpendicular directions, wherein the Z-axis direction is defined as the vertical direction. The aforementioned rotary drive mechanism is mounted on the Y-axis carrier plate 22 of the horizontal drive device 2 to drive the rotary table 3 to rotate about its own central axis.

[0047] In this embodiment, the aforementioned R X The direction is the direction of rotation around the X-axis, R Y The direction is the direction of rotation around the Y-axis, R Z The direction is the direction of rotation around the Z-axis.

[0048] Specifically, the rotary drive mechanism includes a rotary arm 32 and a R... Z Shaft voice coil motor 31, transmission assembly. R ZA shaft voice coil motor 31 is mounted on the Y-axis carrier plate 22 of the horizontal drive device 2 and is connected to the rotary table 3 via a transmission assembly to drive the rotary table 3 to rotate about its own central axis. The transmission assembly includes a rotating arm 32, a bearing 33, and a limiting member 34. The rotating arm 32 extends radially along the rotary table 3 and has a first end connected to the rotary table 3 and a second end away from the first end. The bearing 33 is fitted onto the second end of the rotating arm 32 to be able to rotate about its own central axis. The bearing 33 is a prior art cylindrical gear. The central axis of the bearing 33 extends along the Z-axis direction. Z The shaft voice coil motor 31 has a drive end that moves in a horizontal linear direction. In this embodiment, R Z The driving direction of the shaft voice coil motor 31 is along the X-axis. Z A limiting element 34 is installed on the drive end of the shaft voice coil motor 31. This limiting element 34 and R Z A limiting space 35 is formed between the drive ends of the shaft voice coil motor 31 and the bearing 33. This limiting space 35 has a range of values ​​within R... Z Two limiting sidewalls are arranged opposite each other in the driving direction of the shaft voice coil motor 431. In this embodiment, one sidewall is formed on the limiting member 34, and the other sidewall is formed on R. Z On the drive end of the shaft voice coil motor 431. The aforementioned bearing 33 is housed in the limiting space 35 and is restricted by the limiting space 35 to R. Z The shaft voice coil motor 431 moves in the driving direction. During assembly, the outer circumferential surface of the bearing 33 contacts and engages with the two limiting sidewalls. Through the above structural design, when R... Z When the shaft voice coil motor 431 performs its action, the bearing 33 moves accordingly, thereby causing the rotating shaft to deflect, which in turn causes the rotary table 3 to rotate.

[0049] The aforementioned lifting platform 5 is installed above the rotary platform 3. A lifting guide rail is installed on one side of the rotary platform 3, and a lifting slider 42 is installed on the lifting platform 5. The lifting slider 42 slides with the lifting guide rail, so that the lifting platform 5 has the freedom of movement along the Z-axis. The Z-axis voice coil motor 4 is installed between the rotary platform 3 and the lifting platform 5 to drive the lifting platform 5 to move up and down (i.e., move along the Z-axis). In this embodiment, the Z-axis voice coil motor 4 is installed at the center of the rotary platform 3, and the Z-axis voice coil motor 4 is coaxially arranged with the rotary platform 3.

[0050] The aforementioned wafer stage 6 is mounted above the lifting platform 5. A ball-and-socket leveling assembly 7 connects the wafer stage 6 and the lifting platform 5, including a ball-and-socket seat 71 with a bowl-shaped cavity 711 and a ball head 72 adapted to the bowl-shaped cavity 711. Specifically, the ball-and-socket seat 71 is fixedly mounted on one of the wafer stage 6 and the lifting platform 5, and the ball head 72 is fixedly mounted on the other. The inner wall surface of the bowl-shaped cavity 711 is spherical, and the corresponding ball head 72 has a spherical surface adapted to the inner wall surface of the bowl-shaped cavity 711. A recess 712 is machined at the bottom of the bowl-shaped cavity 711. An air vent is machined on the recess 712 to communicate with the outside. The spherical surface of the ball head 72 slides and seals against the spherical inner wall surface of the bowl-shaped cavity 711, sealing the opening of the recess 712. Through this structural design, the ball-and-socket seat 71 and the ball head 72 can achieve R... X and R Y It allows for a small range of free rotation in the direction, thereby enabling the adjustment of the angle of the wafer stage 6.

[0051] The aforementioned vacuum pumping device 9 is a conventional device of the prior art. It is arranged on one side of the wafer stage 6 and connected to the air port on the cavity 7124 via a pipeline for evacuating the cavity 712422. The vacuum pumping device 9 performs the vacuum pumping operation so that the ball head 72 and the ball cup seat 71 can be vacuum-adhesive and fixed in the mating state, thereby enabling the wafer stage 6 and the lifting platform 5 to be relatively positioned and fixed. Furthermore, a vacuum detection component is installed on the evacuation pipeline to detect the vacuum level within the evacuation pipeline. This vacuum detection component is a vacuum gauge of the prior art. The vacuum level within the cavity 712 is determined to meet the requirements by the detection of the vacuum detection component.

[0052] The aforementioned mask holder 11 is mounted above the wafer stage 6 and is fixedly connected to the base 1 via support side plates 12 on both sides. A mask is mounted on the mask holder 11 corresponding to the wafer stage 6.

[0053] In this embodiment, a gravity-bearing cylinder 43 is mounted on the Y-axis carrier plate 22 of the horizontal drive device 2. This gravity-bearing cylinder 43 is installed on one side of the lifting slider 42, with its drive end extending horizontally. By controlling the movement of the gravity-bearing cylinder 43, it can have two positions: a bearing position where its drive end extends below the lifting platform 5 and bears the lifting platform 5, and a yielding position where its drive end avoids the movement of the lifting platform 5. In this example, in the bearing position, the aforementioned lifting slider 42 and the drive end of the gravity-bearing cylinder 43 are in vertical contact to bear the lifting platform 5. Through this structural design, when the workpiece table experiences a power outage, the drive end of the gravity-bearing cylinder 43 is pushed out to the bearing position to bear all the weight of the lifting platform and its attachments, preventing the overall structure from tilting.

[0054] In this embodiment, a load balancing cylinder 41 is installed between the rotary table 3 and the lifting platform 5. By introducing gas at a reasonable pressure into the load balancing cylinder 41, the gas pushes the piston of the load balancing cylinder 41 to support the lifting platform 5 and its related components, thereby achieving the cancellation (balancing) of the load gravity in the Z-axis direction. The load balancing cylinder 41 can balance almost all the loads on the lifting platform, so that the Z-axis voice coil motor 4 is only responsible for the acceleration, deceleration and leveling contact force of the Z-axis inertial load.

[0055] The workpiece stage in this embodiment includes a leveling ball drive mechanism. This leveling ball drive mechanism is installed on one side of the wafer stage 6 and includes a bracket 81, leveling balls 82, a first driver 83, a sliding seat 84, and a second driver 85. The sliding seat 84 is mounted on the support side plate 12 via a guide rail, allowing it to slide back and forth in the horizontal direction (i.e., the Y-axis direction in this embodiment). The first driver 83 is fixed to the sliding seat 84. The bracket 81 is fixed to the drive end of the first driver 83, enabling it to be driven to move vertically (i.e., move along the Z-axis direction) by the first driver 83. Several leveling balls 82 are mounted on the bracket, each with the same diameter. The aforementioned second driver 85 is fixed to the support side plate 12, and its drive end is connected to the sliding seat 84, driving the sliding seat 84 to move horizontally, thereby moving the bracket 81 and the first driver 83. The bracket 81 has a mating position between the wafer stage 6 and the mask, driven by the second driver 85, and a clearance position away from the wafer stage 6. Before leveling, the support 81 and leveling ball 82 are switched to their mating positions, with the leveling ball 82 sandwiched between the wafer on the wafer stage 6 and the mask on the mask holder 11. The first driver drives the support 81 upwards, causing the leveling ball 82 to contact the mask above. When the wafer stage 6 and the wafer are pushed upwards, the leveling ball 82 contacts the wafer, allowing the wafer stage 6 to correct its orientation via the ball-and-socket leveling assembly, thus achieving parallelism between the wafer on the wafer stage 6 and the mask, completing the leveling process. Three leveling balls 82 are distributed at the three corner points of an equilateral triangle. The first driver 83 and the second driver 85 are conventional components of the prior art.

[0056] The workpiece stage in this embodiment includes a first grating ruler 212 for detecting the position of the horizontal drive device 2 in the X-axis direction, a second grating ruler 222 for detecting the position of the horizontal drive device 2 in the Y-axis direction, a third grating ruler for detecting the rotational position of the rotary table 3, and a fourth grating ruler 421 for detecting the position of the lifting table 5 in the Z-axis direction. The mounting methods of the first grating ruler 212, second grating ruler 222, third grating ruler, and fourth grating ruler 421 are existing technologies. Specifically, the first grating ruler 212 is fixed to the base 1, with its detection end facing the X-axis carrier plate 21. The second grating ruler 222 is fixed to the base 1, with its detection end facing the Y-axis carrier plate 22. The fourth grating ruler 421 is fixed to the lifting slider 42, with its detection end facing the lifting guide rail. The third grating ruler is mounted on the R... Z Behind the shaft voice coil motor module. The first grating ruler 212, the second grating ruler 222, the third grating ruler, and the fourth grating ruler 421 mentioned above serve as position feedback signals to achieve precise alignment control.

[0057] In practical use, the X-axis voice coil motor 211 drives the X-axis carrier plate 21 to move, and the Y-axis voice coil motor 221 drives the Y-axis carrier plate 22 to move, thereby adjusting the position of the rotary table 3 and related components on the rotary table 3 in the X and Y axes. (R...) Z The shaft voice coil motor 431 can drive the rotating arm 32 to swing, which can drive the rotary table 3 to rotate, thereby adjusting the wafer stage 6 in R. Z Position in the direction. Driven by the second driver 85, the leveling ball 82 moves between the wafer stage 6 and the mask. The first driver drives the support 81 upwards, causing the leveling ball 82 to contact the mask above. The Z-axis voice coil motor 4 pushes the lifting platform 5 upwards, thereby moving the wafer stage 6 upwards. When the wafer stage 6 and the wafer are pushed upwards, the three leveling balls 82 contact the wafer. Through the ball holder 71 and ball head 72 automatically correcting the orientation of the wafer stage 6, the wafer stage 6 is positioned in the R-axis direction. X With R Y The wafer stage 6 is rotated freely within a small range in the direction of rotation until it is parallel to the photomask, and the leveling is completed. The vacuum pumping device 9 is activated to create a vacuum adsorption and fixation between the ball cup holder 71 and the ball head 72, thereby positioning and fixing the wafer stage 6 and the lifting platform 5 to maintain the parallel state of the wafer stage 6.

[0058] In the above method, the thrust is estimated directly (almost proportionally) through the current of the Z-axis voice coil motor 4 to form force feedback control. This effectively controls the thrust applied to the lifting platform 5, thereby achieving leveling with minimal leveling contact force and preventing the leveling ball 82 from sticking to the photoresist on the wafer. Movement in the X and Y axes is directly driven by the X-axis voice coil motor 211 and the Y-axis voice coil motor 221, with feedback from the high-precision first grating ruler 212 and the second grating ruler 222 to achieve high-precision movement in the X and Y axes. (R...) Z The thrust is estimated by using the current of the shaft voice coil motor 31 (which is almost proportional) to form force feedback control, which can effectively control the thrust to achieve R Z High-precision movement in the X, Y, Z, and R directions. This structural design replaces conventional mechanical transmission structures, avoiding the complex and time-varying friction forces inherent in mechanical transmissions. Only relatively stable guide rail friction exists, effectively enabling the workpiece stage to move in the X, Y, Z, and R directions. Z It features high-precision motion in the direction and precise control of the leveling contact force, accurate control of the leveling process with high leveling accuracy, and fast and stable leveling process, effectively meeting actual production needs.

[0059] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A workpiece table of proximity contact exposure machine, comprising horizontal driving mechanism, rotary table, lifting table, wafer carrier, Z-axis voice coil motor, mask frame, vacuum pumping device, rotary driving mechanism, ball bowl leveling assembly; characterized in that: the horizontal driving device has freedom of movement along the X-axis direction and the Y-axis direction; the rotary table is arranged on the horizontal driving device and has freedom of rotation about its own central axis; the central axis of the rotary table extends along the Z-axis direction; the rotary driving mechanism is arranged on the horizontal driving device and is used to drive the rotary table to rotate about its own central axis; the lifting table is arranged above the rotary table and has freedom of movement along the Z-axis direction; the Z-axis voice coil motor is arranged between the rotary table and the lifting table and is used to drive the lifting table to move along the Z-axis direction; the wafer carrier is arranged above the lifting table; the ball bowl leveling assembly is arranged between the wafer carrier and the lifting table and comprises a ball bowl seat having a bowl cavity and a ball head matched with the bowl cavity; the bottom of the bowl cavity is provided with a recess; the spherical surface of the ball head is in sliding sealing cooperation with the spherical inner wall surface of the bowl cavity and seals the recess; of the wafer carrier and the lifting table, one is provided with the ball bowl seat and the other is provided with the ball head; the vacuum pumping device is in communication with the recess and is used to pump the recess; the mask frame is arranged above the wafer carrier and the mask frame is provided with a mask corresponding to the wafer carrier. The horizontal driving device comprises an X-axis driving device and a Y-axis driving device; the X-axis driving device comprises an X-axis carrier plate and an X-axis voice coil motor used to drive the X-axis carrier plate to move along the X-axis direction; the Y-axis driving device comprises a Y-axis carrier plate movably arranged on the X-axis carrier plate and a Y-axis voice coil motor arranged on the X-axis carrier plate and used to drive the Y-axis carrier plate to move along the Y-axis direction; the rotary table is arranged on the X-axis carrier plate or the Y-axis carrier plate. The workpiece table comprises a gravity bearing cylinder; the gravity bearing cylinder is arranged on the horizontal driving device and has a bearing position at which the driving end of the gravity bearing cylinder extends to below the lifting table and bears the lifting table, and has an avoiding position at which the driving end of the gravity bearing cylinder avoids the movement of the lifting table. The workpiece table comprises a load balancing cylinder; the load balancing cylinder is connected between the rotary table and the lifting table. The workpiece table comprises a leveling ball transmission mechanism; the leveling ball transmission mechanism comprises a support, a plurality of leveling balls arranged on the support, a first driver connected with the support and used to drive the support to move up and down, and a second driver used to drive the first driver to move along the horizontal direction; the support has a matching position at which the support moves to between the wafer carrier and the mask under the drive of the second driver, and an avoiding position away from the wafer carrier; the diameters of the leveling balls are consistent. The leveling balls are three and are distributed on three corner points of an equilateral triangle. The workpiece table comprises a first grating ruler used to detect the position of the horizontal driving device along the X-axis direction, a second grating ruler used to detect the position of the horizontal driving device along the Y-axis direction, a third grating ruler used to detect the rotary position of the rotary table, and a fourth grating ruler used to detect the position of the lifting table along the Z-axis direction. ​ ​ ​ 2. A stage for a proximity exposure tool according to claim 1, wherein: ​ 3. The stage of a proximity exposure tool according to claim 1, wherein: The rotating driving mechanism comprises a rotating arm, R Z The rotating driving mechanism comprises a rotating arm, R Z The rotating driving mechanism comprises a rotating arm, R 4. The stage of a proximity contact exposure apparatus according to claim 3, wherein: The transmission assembly comprises a rotating arm and a bearing; the rotating arm has a first end connected with the rotating table and a second end away from the first end; the bearing is arranged at the second end of the rotating arm and rotates around a central axis thereof; the central axis of the bearing extends along the Z-axis direction; the R Z The voice coil motor has a driving end moving along a horizontal linear direction; the R Z The voice coil motor is provided with a limiting space on the driving end; the bearing is accommodated in the limiting space and is limited by the limiting space in the R Z The voice coil motor is movable in the driving direction.

5. A stage for a proximity exposure tool according to claim 4, wherein: The limiting space has a distance R Z Two limiting side walls are oppositely arranged in the driving direction of the shaft voice coil motor; the outer circumferential surface of the bearing is in contact with the two limiting side walls respectively.

6. The stage of a proximity exposure tool according to claim 1, wherein: ​ 7. The stage of a proximity exposure tool according to claim 1, wherein: ​ 8. The stage of a proximity exposure tool according to claim 1, wherein: ​ 9. A stage for a proximity exposure tool according to claim 8, wherein: ​ 10. The stage of a proximity exposure tool according to claim 1, wherein: ​

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