Workpiece table of proximity contact type exposure machine

Abstract

The invention discloses a workpiece table of a proximity contact type exposure machine. A horizontal driving device has a degree of freedom of movement along an X-axis direction and a Y-axis direction; the rotating table has the freedom degree of rotating around the central axis of the rotating table. The lifting table is arranged above the rotating table and has the degree of freedom of moving in the Z-axis direction; the Z-axis voice coil motor is arranged between the rotating table and the lifting table and used for driving the lifting table to move in the Z-axis direction. The ball bowl leveling assembly is arranged between the wafer carrying table and the lifting table and comprises a ball bowl seat with a bowl-shaped cavity and a ball head matched with the bowl-shaped cavity; a concave cavity is formed in the bottom of the bowl-shaped cavity; the spherical surface of the ball head is in sliding sealing fit with the spherical inner wall surface of the bowl-shaped cavity and seals the concave cavity; the mask frame is arranged above the wafer carrying table. According to the invention, the relative position and posture between the mask plate and the wafer can be adjusted, the accurate control of the leveling process is realized, the high-precision movement of four degrees of freedom of X / Y / Z / RZ is effectively realized, the accurate control of the leveling contact force is realized, and the practicability is high.

Description

Technical Field

[0001] The present invention relates to the technical field of photolithography machines, and in particular to a workpiece table of a proximity contact exposure machine. Background Art

[0002] Proximity exposure means that a tiny gap (Gap) is left between the mask and the photoresist substrate, and the Gap is about 0-200μm. It can effectively avoid damage to the mask caused by direct contact with the photoresist, making the mask and the photoresist substrate durable, with a long mask life (which can be increased by more than 10 times) and fewer pattern defects. Proximity exposure is the most widely used in modern photolithography.

[0003] Proximity mask exposure requires precise adjustment of the relative position between the mask and the wafer (the marks on the mask and the wafer overlap in the projection direction) and the posture (the mask and the wafer are parallel) to ensure a uniform exposure gap, thereby ensuring a better exposure effect. X With R Y Three equal-diameter leveling balls arranged in an equilateral triangle are sandwiched between the mask and the wafer to achieve leveling through mechanical contact to ensure the parallel relationship between the mask and the wafer; the relative position of X / Y / Z and R Z The adjustment of direction and attitude mainly relies on high-precision X / Y / Z / R Z The two most important requirements in the whole leveling and alignment process are: a. During the leveling process, the contact force between the leveling ball and the wafer should be kept as small as possible to avoid the leveling ball sticking to the photoresist on the wafer; b. During the alignment process, high precision and speed should be ensured to ensure the performance and yield of the exposure product.

[0004] The Chinese invention patent with application number 202210842328.2 discloses a device for rotating and lifting alignment based on ball splines. It uses a stepper motor combined with a ball screw to achieve X / Y / R Z Three degrees of freedom of movement, the Z direction uses a servo motor combined with a ball spline structure to achieve Z-direction precision movement and thrust control during leveling. ZThe four degrees of freedom of motion all introduce mechanical transmission structures. On the one hand, the machining accuracy of the mechanical transmission structure itself is far lower than the required motion accuracy (the difference is about one order of magnitude). The introduction of mechanical transmission cannot directly guarantee the required motion accuracy. It is necessary to add a grating ruler at the end of the actuator to feedback and achieve high-precision control. The inherent deformation and gap of the mechanical transmission structure itself put forward higher requirements for control and reduce the alignment speed (a higher number of alignments is required to achieve accurate alignment under the same single alignment time). On the other hand, since the thrust of the Z axis during the leveling process relies on the servo motor current feedback to achieve contact force control, the unstable friction force in the mechanical transmission structure poses a greater challenge to the control of the leveling contact force, and the contact force cannot be accurately controlled. Summary of the invention

[0005] In view of the above-mentioned technical problems, the purpose of the present invention is to propose a workpiece stage close to a contact exposure machine, which can adjust the relative position and posture between the mask plate and the wafer, and realize precise control of the leveling process, effectively realizing X / Y / Z / R Z High-precision motion in four degrees of freedom and precise control of leveling contact force make it highly practical.

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

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

[0008] The rotating table is arranged on the horizontal driving device and has the freedom to rotate around its own central axis; the central axis of the rotating table extends along the Z-axis direction;

[0009] The rotation drive mechanism is arranged on the horizontal drive device and is used to drive the rotating table to rotate around its own central axis;

[0010] The lifting platform is arranged above the rotating platform and has the freedom to move along the Z-axis direction;

[0011] The Z-axis voice coil motor is arranged between the rotating platform and the lifting platform, and is used to drive the lifting platform to move along the Z-axis direction;

[0012] The wafer carrier is arranged above the lifting platform;

[0013] The ball bowl leveling assembly is arranged between the wafer carrier and the lifting platform, and comprises a ball bowl seat with a bowl-shaped cavity and a ball head adapted to the bowl-shaped cavity; a concave cavity is arranged at the bottom of the bowl-shaped cavity; the spherical surface of the ball head and the spherical inner wall surface of the bowl-shaped cavity are slidably sealed and cooperated to close the concave cavity; the ball bowl seat is arranged on one of the wafer carrier and the lifting platform, and the ball head is arranged on the other;

[0014] The vacuum pumping device is in communication with the concave cavity and is used to vacuum the concave cavity;

[0015] The mask frame is arranged above the wafer stage, and a mask is arranged on the mask frame corresponding to the wafer stage.

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

[0017] Furthermore, the rotation drive mechanism includes a rotating arm, R Z Axis voice coil motor, transmission assembly; said R Z The shaft voice coil motor is arranged on the horizontal driving device and is connected to the rotating table through the transmission assembly to drive the rotating 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 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 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 driving end that moves in a horizontal straight line direction; the R Z A limiting space is provided on the driving end of the shaft voice coil motor; the bearing is accommodated in the limiting space and is limited by the limiting space to R Z The shaft moves in the driving direction of the voice coil motor.

[0019] Furthermore, the limiting space has a Z The shaft voice coil motor has two limiting side walls arranged opposite to each other in the driving direction; the outer peripheral surface of the bearing is in contact with and matched with the two limiting side walls respectively.

[0020] Furthermore, the workpiece platform includes a gravity-bearing cylinder; the gravity-bearing cylinder is arranged on the horizontal driving device, and has a carrying position in which its driving end extends to the bottom of the lifting platform and supports the lifting platform, and has an avoidance position in which its driving end avoids the movement of the lifting platform.

[0021] Furthermore, the workpiece platform includes a load balancing cylinder; the load balancing cylinder is connected between the rotating platform and the lifting platform.

[0022] Furthermore, the workpiece table includes a leveling ball transmission mechanism; the leveling ball transmission mechanism includes a bracket, a plurality of leveling balls arranged 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 in a horizontal direction; the bracket has the ability to move to a matching position between the wafer carrier and the mask plate under the drive of the second driver, and an avoidance position away from the wafer carrier; the diameters of each of the leveling balls are consistent.

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

[0024] Furthermore, the workpiece stage includes a first grating scale for detecting the position of the horizontal drive device in the X-axis direction, a second grating scale for detecting the position of the horizontal drive device in the Y-axis direction, a third grating scale for detecting the rotation position of the rotating stage, and a fourth grating scale for detecting the position of the lifting platform 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. The present invention uses a Z-axis voice coil motor to push the lifting platform to move up and down, and directly estimates the thrust (almost proportional) through the current of the Z-axis voice coil motor to form force feedback control, which can effectively control the thrust applied to the lifting platform, and then can achieve leveling with the minimum leveling contact force, avoiding the leveling ball from sticking to the photoresist on the wafer. In addition, it replaces the conventional mechanical transmission structure, avoids the complex time-varying friction in the mechanical transmission structure, and only has a relatively stable guide rail friction, effectively realizing the high-precision movement of the lifting platform in the Z-axis direction and the precise control of the leveling contact force, and has strong practicality.

[0027] 2. The present invention can adjust the positions of the turntable and related components on the turntable in the X-axis and Y-axis directions through the coordinated use of the X-axis voice coil motor and the Y-axis voice coil motor, directly promote the movement in the X-axis and Y-axis directions through the X-axis voice coil motor and the Y-axis voice coil motor, and utilize the high-precision first grating scale and the second grating scale for feedback to achieve high-precision movement in the X-axis and Y-axis directions. The X-axis voice coil motor and the Y-axis voice coil motor are arranged as close as possible to the middle of the X-axis carrier plate and the Y-axis carrier plate, so that the bias torque is smaller, the structural deformation is smaller, and the practicability is strong.

[0028] 3. The present invention is achieved by R Z The use of shaft voice coil motor and transmission assembly, R ZThe axial voice coil motor can drive the rotating arm to swing, which can drive the rotating table to rotate, and then adjust the wafer stage in R Z The position in the direction and through R Z The high-precision grating scale of the axis voice coil motor forms feedback to achieve R Z High-precision movement in direction, strong practicality.

[0029] 4. The present invention can realize the wafer stage in R by using the ball bowl seat and the ball head in combination. X With R Y The wafer stage can rotate freely in a small range in the direction. When the wafer stage, leveling ball and mask plate are in contact, the posture of the wafer stage can be automatically corrected to make it parallel to the mask plate. And by evacuating the vacuum to form a vacuum adsorption fixation between the ball bowl seat and the ball head, the wafer stage and the lifting platform are positioned and fixed to each other, so that the wafer stage remains parallel. The combination of the above methods can achieve precise control of the contact force during the leveling process, high leveling accuracy, fast and stable leveling process, and effectively meet actual production needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The technical solution of the present invention is further described below in conjunction with the accompanying drawings:

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

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

[0033] Figure 3 It is a three-dimensional structural schematic diagram of the horizontal driving device and the rotating platform of the present invention;

[0034] Figure 4 for Figure 3 A schematic diagram of a three-dimensional structure from another perspective;

[0035] Figure 5 for Figure 3 A schematic diagram of a three-dimensional structure from another perspective;

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

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

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

[0039] Fig. 9It is a cross-sectional structural schematic diagram of the wafer stage, lifting seat and ball bowl leveling assembly of the present invention;

[0040] Fig.10 It is a schematic diagram of the three-dimensional structure of the ball bowl seat of the present invention;

[0041] Fig.11 It is a schematic diagram of the three-dimensional structure of the ball head of the present invention;

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

[0043] The preferred embodiments of the present invention are described in detail below in conjunction with 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 making a clearer and more definite definition of the protection scope of the present invention.

[0044] like Figure 1-11The workpiece table of a close contact exposure machine described in this embodiment is shown, including a base 1, a horizontal drive mechanism, a rotating table 3, a lifting table 5, a wafer carrier 6, a Z-axis voice coil motor 4, a mask frame 11, a vacuum device 9, a rotating drive mechanism, and a bowl leveling assembly 7. Among them, the horizontal drive device 2 is installed on the base 1. The horizontal drive device 2 has the degree of freedom to move along the X-axis direction and the Y-axis direction, so that it can move along the X-axis direction and the Y-axis direction. 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 21 and an X-axis voice coil motor 211. The X-axis carrier 21 is installed on the base 1 through a guide rail slider mechanism so that it can move along the X-axis direction. The X-axis voice coil motor 211 is fixed on the base 1, and its driving end is connected to the X-axis carrier 21 to drive the X-axis carrier 21 to move along the X-axis direction. The aforementioned Y-axis drive device includes a Y-axis carrier 22 and a Y-axis voice coil motor 221. The Y-axis carrier plate 22 is mounted on the X-axis carrier plate 21 through a guide rail and slider mechanism so as to be movable along the Y-axis direction. The aforementioned Y-axis voice coil motor 221 is fixed to the X-axis carrier plate 21, and its driving 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 to the middle position of the X-axis carrier plate 21 as possible, and the Y-axis voice coil motor 221 is arranged as close to the middle position of the Y-axis carrier plate 22 as possible to reduce the torsional torque on the respective guide rails when offset.

[0046] The aforementioned rotating table 3 is mounted on the Y-axis carrier plate 22 of the horizontal driving device 2 through the bearing 33 so as to have the freedom to rotate around its own central axis. The central axis of the rotating table 3 is defined as extending along the Z-axis direction. In this embodiment, the X-axis, the Y-axis, and the Z-axis are mutually perpendicular directions, wherein the Z-axis direction is defined as the vertical direction. The aforementioned rotation drive mechanism is mounted on the Y-axis carrier plate 22 of the horizontal driving device 2 to drive the rotating table 3 to rotate around 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, R Z Axis voice coil motor 31, transmission assembly. ZThe axial voice coil motor 31 is installed on the Y-axis carrier plate 22 of the horizontal driving device 2, and is connected to the rotating table 3 through a transmission assembly to drive the rotating table 3 to rotate around its own central axis. The transmission assembly includes a rotating arm 32, a bearing 33, and a stopper 34. The rotating arm 32 extends radially along the rotating table 3, and has a first end connected to the rotating table 3 and a second end away from the first end. The bearing 33 is sleeved on the second end of the rotating arm 32 so that it can rotate around its own central axis. The bearing 33 is a cylindrical gear of the prior art. The central axis of the bearing 33 extends along the Z-axis direction. Z The shaft voice coil motor 31 has a driving end that moves in a horizontal straight line direction. Z The driving direction of the axis voice coil motor 31 is along the X-axis direction. Z A limit member 34 is installed on the driving end of the shaft voice coil motor 31. The limit member 34 and the R Z A limiting space 35 adapted to the bearing 33 is formed between the driving end of the shaft voice coil motor 31. The limiting space 35 has a Z The two limiting side walls are arranged opposite to each other in the driving direction of the axis voice coil motor 431. In this embodiment, one of the side walls is formed on the limiting member 34, and the other side wall is formed on the R Z The bearing 33 is accommodated in the limiting space 35 and is limited by the limiting space 35 to R Z The shaft voice coil motor 431 moves in the driving direction. During the specific assembly, the outer peripheral surface of the bearing 33 is in contact with the two limiting side walls respectively. Through the above structural design, when R Z When the shaft voice coil motor 431 is in operation, the bearing 33 moves accordingly, thereby driving the rotating shaft to deflect, and further driving the rotating platform 3 to rotate.

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

[0050] The aforementioned wafer carrier 6 is installed above the lifting platform 5, and the ball bowl leveling assembly 7 is connected between the wafer carrier 6 and the lifting platform 5, including a ball bowl seat 71 with a bowl-shaped cavity 711 and a ball head 72 adapted to the bowl-shaped cavity 711. Among them, the ball bowl seat 71 is fixedly installed on one of the wafer carrier 6 and the lifting platform 5, and the ball head 72 is fixedly installed on the other. The inner wall surface of the bowl-shaped cavity 711 is a spherical surface, and the corresponding ball head 72 has a spherical surface adapted to the inner wall surface of the bowl-shaped cavity 711. A concave cavity 712 is machined at the bottom of the bowl-shaped cavity 711. An air port connected to the outside is machined on the concave cavity 712. The spherical surface of the ball head 72 is slidably sealed with the spherical inner wall surface of the bowl-shaped cavity 711, and the open end of the concave cavity 712 is closed. Through the above-mentioned structural design, the ball bowl seat 71 and the ball head 72 can be spaced apart at R X and R Y The wafer stage 6 can be freely rotated in a small range in the direction, thereby achieving angle adjustment of the wafer stage 6.

[0051] The aforementioned vacuum pumping device 9 is a conventional device of the prior art, which is arranged on one side of the wafer carrier 6 and is connected to the air port on the concave cavity 7124 through a pipeline, so as to be used for vacuuming the concave cavity 712422. The vacuum pumping operation is performed by the vacuum pumping device 9, so that the ball head 72 and the ball bowl seat 71 can be fixed by vacuum adsorption when in a mating state, so that the wafer carrier 6 and the lifting platform 5 can be relatively positioned and fixed. In addition, a vacuum detection component for detecting the vacuum degree in the vacuum pipeline is installed on the exhaust pipeline. The vacuum detection component is a negative pressure gauge of the prior art. Through the detection of the vacuum detection component, it is determined whether the vacuum degree in the concave cavity 712 meets the requirements.

[0052] The aforementioned mask rack 11 is installed above the wafer stage 6, and is fixedly connected to the base 1 through the supporting side plates 12 on both sides. A mask is installed on the mask rack 11 corresponding to the wafer stage 6.

[0053] In this embodiment, a gravity-bearing cylinder 43 is installed on the Y-axis carrier plate 22 of the horizontal drive device 2. The gravity-bearing cylinder 43 is installed on one side of the lifting slider 42, and its driving end extends in the horizontal direction. By controlling the movement of the gravity-bearing cylinder 43, the gravity-bearing cylinder 43 has a bearing position in which its driving end extends below the lifting platform 5 and bears the lifting platform 5, and has an avoidance position in which its driving end avoids the movement of the lifting platform 5. In this example, in the bearing position, the aforementioned lifting slider 42 abuts against the driving end of the gravity-bearing cylinder 43 up and down to be able to bear the lifting platform 5. Through the above-mentioned structural design, when the workpiece platform is cut off from air and power, the driving end of the gravity-bearing cylinder 43 is pushed out to the bearing position so as to be able to bear all the gravity of the lifting platform and its accessories, so as to prevent the overall structure from being skewed.

[0054] In this embodiment, a load balancing cylinder 41 is installed between the rotating table 3 and the lifting platform 5. By introducing gas of 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 related components thereon, so as to achieve the offset (balance) 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 and deceleration of the Z-axis inertial load and the leveling contact force.

[0055] The workpiece stage of this embodiment includes a leveling ball transmission mechanism. The leveling ball transmission mechanism is installed on one side of the wafer stage 6, and includes a bracket 81, a leveling ball 82, a first driver 83, a sliding seat 84, and a second driver 85. The sliding seat 84 is installed on the supporting side plate 12 through a guide rail so as to be able to slide back and forth in the horizontal direction (i.e., the Y-axis direction of this embodiment). The first driver 83 is fixed on the sliding seat 84. The bracket 81 is fixed on the driving end of the first driver 83 so as to be able to drive the lifting movement (i.e., move in the Z-axis direction) by the first driver 83. Several leveling balls 82 are installed on the bracket, and the diameters of each leveling ball 82 are consistent. The aforementioned second driver 85 is fixed on the supporting side plate 12, and its driving end is connected to the sliding seat 84 to drive the sliding seat 84 to move in the horizontal direction, thereby driving the bracket 81 and the first driver 83 to move. The bracket 81 has a matching position between the wafer stage 6 and the mask plate driven by the second driver 85, and a avoidance position away from the side of the wafer stage 6. Among them, before leveling, the bracket 81 and the leveling ball 82 are switched to the matching position, and the leveling ball 82 is clamped between the wafer on the wafer carrier 6 and the mask plate on the mask plate holder 11. The bracket 81 is driven upward by the first driver so that the leveling ball 82 contacts the mask plate above. When the wafer carrier 6 and the wafer are pushed upward, the leveling ball 82 contacts the wafer so that the wafer carrier 6 corrects its posture through the ball bowl leveling assembly, so that the wafer and the mask plate on the wafer carrier 6 can be parallel to each other, and the leveling is completed. The aforementioned leveling balls 82 are 3, distributed at the three corner points of an equilateral triangle. The above-mentioned first driver 83 and second driver 85 are conventional components of the prior art.

[0056] The workpiece stage of this embodiment includes a first grating scale 212 for detecting the position of the horizontal drive device 2 in the X-axis direction, a second grating scale 222 for detecting the position of the horizontal drive device 2 in the Y-axis direction, a third grating scale for detecting the rotation position of the rotating table 3, and a fourth grating scale 421 for detecting the position of the lifting platform 5 in the Z-axis direction. The installation method of the above-mentioned first grating scale 212, second grating scale 222, third grating scale and fourth grating scale 421 is the existing technology. Specifically, the above-mentioned first grating scale 212 is fixed on the base 1, and its detection end is arranged facing the X-axis carrier plate 21. The second grating scale 222 is fixed on the second grating scale 222, and its detection end is arranged facing the Y-axis carrier plate 22. The fourth grating scale 421 is fixed on the lifting slider 42, and its detection end faces the lifting guide rail. The third grating scale is installed on the R Z The first grating ruler 212, the second grating ruler 222, the third grating ruler and the fourth grating ruler 421 are used as position feedback signals to realize precise positioning control.

[0057] In specific use, the X-axis voice coil motor 211 drives the X-axis carrier 21 to move, and the Y-axis voice coil motor 221 drives the Y-axis carrier 22 to move, so as to adjust the positions of the rotating table 3 and related components on the rotating table 3 in the X-axis and Y-axis directions. Z The axis voice coil motor 431 can drive the rotating arm 32 to swing, and can drive the rotating table 3 to rotate, thereby adjusting the wafer carrier 6 in the R Z The second driver 85 drives the leveling ball 82 to move between the wafer carrier 6 and the mask. The first driver drives the bracket 81 to move upward, so that the leveling ball 82 contacts the mask above. The Z-axis voice coil motor 4 pushes the lifting platform 5 to move upward to drive the wafer carrier 6 to move upward. When the wafer carrier 6 and the wafer are pushed upward, the three leveling balls 82 contact the wafer. Through the ball bowl seat 71 and the ball head 72, the posture of the wafer carrier 6 is automatically corrected to achieve the wafer carrier 6 in R X With R Y The wafer carrier 6 and the lifting platform 5 are fixed to each other so that the wafer carrier 6 remains parallel to the mask.

[0058] In the above method, the thrust is estimated directly through the current of the Z-axis voice coil motor 4 (almost proportional) to form force feedback control, which can effectively control the thrust applied to the lifting platform 5, and then achieve leveling with the minimum leveling contact force to avoid the leveling ball 82 sticking to the photoresist on the wafer. The X-axis voice coil motor 211 and the Y-axis voice coil motor 221 are directly used to promote the movement in the X-axis and Y-axis directions, and the high-precision first grating scale 212 and the second grating scale 222 are used for feedback to achieve high-precision movement in the X-axis and Y-axis directions. Through R Z The thrust is estimated by the current of the shaft voice coil motor 31 (almost proportional) to form force feedback control, which can effectively control the thrust to achieve Z In the above structural design, the conventional mechanical transmission structure is replaced to avoid the complex time-varying friction in the mechanical transmission structure. Only a relatively stable guide rail friction exists, which effectively realizes the workpiece table in the X-axis direction, Y-axis direction, Z-axis direction, R Z High-precision movement in direction and precise control of leveling contact force, precise control of the leveling process and high leveling accuracy, the leveling process is fast and stable, effectively meeting actual production needs.

[0059] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A workpiece stage close to a contact exposure machine, comprising a horizontal drive mechanism, a rotating table, a lifting table, a wafer carrier, a Z-axis voice coil motor, a mask frame, a vacuum pumping device, a rotating drive mechanism, and a bowl leveling assembly; characterized in that: The horizontal drive device has the freedom to move along the X-axis direction and the Y-axis direction; The rotating table is arranged on the horizontal driving device and has the freedom to rotate around its own central axis; the central axis of the rotating table extends along the Z-axis direction; The rotation drive mechanism is arranged on the horizontal drive device and is used to drive the rotating table to rotate around its own central axis; The lifting platform is arranged above the rotating platform and has the freedom to move along the Z-axis direction; The Z-axis voice coil motor is arranged between the rotating platform and the lifting platform, and is used to drive the lifting platform to move along the Z-axis direction; The wafer carrier is arranged above the lifting platform; The ball bowl leveling assembly is arranged between the wafer carrier and the lifting platform, and comprises a ball bowl seat with a bowl-shaped cavity and a ball head adapted to the bowl-shaped cavity; a concave cavity is arranged at the bottom of the bowl-shaped cavity; the spherical surface of the ball head and the spherical inner wall surface of the bowl-shaped cavity are slidably sealed and cooperated to close the concave cavity; the ball bowl seat is arranged on one of the wafer carrier and the lifting platform, and the ball head is arranged on the other; The vacuum pumping device is in communication with the concave cavity and is used to vacuum the concave cavity; The mask frame is arranged above the wafer stage, and a mask is arranged on the mask frame corresponding to the wafer stage.

2. The workpiece stage of a proximity contact exposure machine according to claim 1, characterized in that: The horizontal driving device includes an X-axis driving device and a Y-axis driving device; the X-axis driving device includes an X-axis carrier and an X-axis voice coil motor for driving the X-axis carrier to move along the X-axis direction; the Y-axis driving device includes a Y-axis carrier movably arranged on the X-axis carrier, and a Y-axis voice coil motor arranged on the X-axis carrier and used to drive the Y-axis carrier to move along the Y-axis direction; the rotating table is arranged on the X-axis carrier or the Y-axis carrier.

3. The workpiece stage of a proximity contact exposure machine according to claim 1, characterized in that: The rotary drive mechanism includes a rotary arm, Z Axis voice coil motor, transmission assembly; said R Z The shaft voice coil motor is arranged on the horizontal driving device and is connected to the rotating table through the transmission assembly to drive the rotating table to rotate around its own central axis.

4. The workpiece stage of a proximity contact exposure machine according to claim 3, characterized in that: The transmission assembly includes a rotating arm and a bearing; the rotating arm has a first end connected to 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 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 driving end that moves in a horizontal straight line direction; the R Z A limiting space is provided on the driving end of the shaft voice coil motor; the bearing is accommodated in the limiting space and is limited by the limiting space to R Z The shaft moves in the driving direction of the voice coil motor.

5. The workpiece stage of a proximity contact exposure machine according to claim 4, characterized in that: The confined space has a Z The shaft voice coil motor has two limiting side walls arranged opposite to each other in the driving direction; the outer peripheral surface of the bearing is in contact with and matched with the two limiting side walls respectively.

6. The workpiece stage of a proximity contact exposure machine according to claim 1, characterized in that: The workpiece platform includes a gravity-bearing cylinder; the gravity-bearing cylinder is arranged on a horizontal driving device, and has a carrying position in which its driving end extends below the lifting platform and bears the lifting platform, and has an avoidance position in which its driving end avoids the movement of the lifting platform.

7. The workpiece stage of a proximity contact exposure machine according to claim 1, characterized in that: The workpiece platform comprises a load balancing cylinder; the load balancing cylinder is connected between the rotating platform and the lifting platform.

8. The workpiece stage of a proximity contact exposure machine according to claim 1, characterized in that: The workpiece table includes a leveling ball transmission mechanism; the leveling ball transmission mechanism includes a bracket, a plurality of leveling balls arranged 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 in a horizontal direction; the bracket has the ability to move to a matching position between the wafer carrier and the mask plate under the drive of the second driver, and an avoidance position away from the wafer carrier; the diameters of each of the leveling balls are consistent.

9. The workpiece stage of a proximity contact exposure machine according to claim 8, characterized in that: There are three leveling balls distributed on three corner points of an equilateral triangle.

10. The workpiece stage of a proximity contact exposure machine according to claim 1, characterized in that: The workpiece stage includes a first grating scale for detecting the position of the horizontal driving device in the X-axis direction, a second grating scale for detecting the position of the horizontal driving device in the Y-axis direction, a third grating scale for detecting the rotation position of the rotating stage, and a fourth grating scale for detecting the position of the lifting platform in the Z-axis direction.

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