CN105487347A - Spring-damping-based dynamic-magnetic-steel magnetic levitation dual-stage vector arc switching method and device - Google Patents

Abstract

The moving magnet steel magnetic levitation double workpiece table vector arc transfer method and device based on spring damping belong to the semiconductor manufacturing equipment technology. The two workpiece tables work between the measurement position and the exposure position. The position of the workpiece table is measured by a flat grating, and the passive compensation structure composed of four sets of flat leaf springs is used to compensate the movement of the balance mass. The workpiece table adopts a moving magnet steel type. Driven by a magnetic levitation planar motor, in the process of exchanging double workpiece tables, a planar motor is used to drive two workpiece tables to realize a single-beat arc rapid exchange; Long stabilization time and other problems, reduce the link of changing the stage, shorten the time of changing the stage, and improve the productivity of the lithography machine.

Description

Method and device for moving magnetic steel magnetic levitation double workpiece table vector circular arc table changing based on spring damping

technical field

The invention belongs to the technical field of semiconductor manufacturing equipment, and mainly relates to a method and a device for a moving magnet steel maglev double workpiece table vector arc return conversion table based on spring damping.

Background technique

Lithography machine is one of the important ultra-precision equipment in the manufacture of very large scale integrated circuits. As the key subsystem of the lithography machine, the workpiece table largely determines the resolution, overlay accuracy and productivity of the lithography machine.

Productivity is one of the main goals of lithography machine development. Under the condition of satisfying the resolution and overlay accuracy, improving the operating efficiency of the workpiece table and thus improving the productivity of the lithography machine is the development direction of the workpiece table technology. The most direct way to improve the operating efficiency of the workpiece table is to increase the motion acceleration and speed of the workpiece table, but in order to ensure the original accuracy, the speed and acceleration cannot be increased without limit. The initial workpiece table only had one silicon wafer carrier, and the lithography machine could only process one silicon wafer at a time. All processes were processed serially, and the production efficiency was low. For this reason, someone has proposed a double worktable technology, which is also the mainstream technical means to improve the production efficiency of lithography machines. The double worktable technology has two work stations for exposure and pretreatment and two workbenches on the workbench. The exposure and measurement adjustment can be processed in parallel, which greatly shortens the time and improves the production efficiency. The current representative product is the lithography machine based on the Twinscan technology, that is, the double-workpiece technology of ASML company in the Netherlands.

Improving the operating efficiency of the double workpiece table is one of the development goals of the current lithography machine workpiece table technology. The double workpiece table technology involves the problem of switching the workpiece table between two stations, and the efficiency of table switching directly affects the operating efficiency of the workpiece table of the lithography machine, that is, the productivity of the lithography machine. How to reduce the interference of channel switching to other systems while shortening the channel switching time as much as possible has always been the focus of research. In the traditional double-table switching process, the workpiece table is linearly driven in the exposure and pretreatment processes. In the dual-stage patents US2001/0004105A1 and W098/40791, each workpiece table has two interchangeable and coordinated units to achieve double-stage The exchange of the workpiece table improves the productivity without increasing the movement speed of the workpiece table. However, due to the coupling connection between the workpiece table and the guide rail, the workpiece table and the drive unit will be separated temporarily during the table change process, which will affect the workpiece table. The positioning accuracy has a great influence. At the same time, the motion unit and guide rail are longer, and the motion mass is larger, which has adverse effects on the improvement of motion speed and acceleration. Chinese patent CN101609265 proposes a planar motor-driven multiple exchange system for wafer stages. The stator of the planar motor is arranged on the top of the base stage, and the mover is arranged at the bottom of the wafer stage. Compared with the linear motor drive, there is no separation between the workpiece stage and the drive unit. Separation; Chinese patent CN101694560 proposes a dual-table exchange system driven by an air-supported permanent magnet planar motor. The workpiece table is driven by a planar motor and supported by air flotation, which avoids the separation of the drive unit and the workpiece table during the aforementioned table-changing process The problem is that the running resistance of the workpiece table is reduced, the driving current of the planar motor is reduced, and the problem of heat dissipation is reduced.

The above-mentioned patent adopts a straight-line table-changing scheme when changing tables, and the back-turning table-changing scheme has unique advantages over the straight-line table-changing scheme, so a double-workpiece table technology using a back-turning table appears. Chinese patent CN101071275 adopts the method of rotating the whole abutment to realize the transposition of the double workpiece table, which simplifies the system structure, and at the same time, the movement of the two workpiece tables has no overlapping area, avoiding the potential safety hazard of collision. However, there are problems such as large moment of inertia, difficulty in precise positioning of high-power rotary motors, and high heat generation that cause system temperature rise by rotating the entire base to achieve workpiece table transposition. At the same time, the radius of rotation is large, which significantly increases the main structure of the lithography machine. Chinese patent CN102495528 adopts a rotary transfer table in the center of the abutment to complete the exchange of double workpiece tables. The table change is divided into three beats, which improves the efficiency of the table change. However, the structure of the rotary transfer table is complicated and the rotary positioning accuracy is low.

In order to prevent the drift of the balance mass, the US patent US7034920B2 uses a linear push rod motion compensation mechanism and an eccentric wheel motion compensation mechanism. The linear push rod motion compensation mechanism is simple in principle and intuitive to control, but it cannot inhibit Rz rotation. The eccentric wheel motion compensation mechanism Four rotating servo motors are used to control the movement of the balance mass in a relatively small plane range through the eccentric wheel. The movement includes degrees of freedom in the X, Y and Rz directions, but this structure requires the decoupling of the four motors. The consistency of the motor and the control requirements of the motor are relatively high. The passive compensation does not need position detection and active control, which reduces the cost, improves the reliability and simplifies the structure.

Contents of the invention

Aiming at the deficiencies of the above-mentioned prior art, the present invention proposes a method and device for moving magnetic steel magnetic levitation double workpiece table vector arc return conversion table based on spring damping, so as to achieve single-beat rapid arc change of workpiece table and reduce the number of changeover tables. The purpose of improving the production rate of the lithography machine is to reduce the stage link, shorten the time for changing the stage, and effectively improve the productivity of the lithography machine.

The purpose of the present invention is achieved like this:

A method for moving magnetic steel magnetic levitation double worktables based on spring damping and vector circular arc transfer, the method includes the following steps: in the initial working state, the first worktable at the measurement position is in the pre-aligned state, and the second workbench at the exposure position is in the Exposure state: the first step, after the pre-alignment of the first workpiece table at the measurement position, it is driven by the moving magnetic steel to move to the predetermined position A of the measurement position for changing the table, charging and waiting. Drive and move to the predetermined position C of the exposure position; in the second step, the first workpiece table and the second workpiece table move counterclockwise along the circular arc track through the vector control of the plane motor. During the movement, the phase of the two workpiece tables does not change. The moving position is measured by the plane grating. When the first workpiece table is driven by the moving magnetic steel to move to the predetermined position C of the exposure position, and the second workpiece table is driven by the moving magnetic steel to move to the predetermined position D of the measurement position, the stage change is completed, and the first The workpiece stage performs silicon wafer lithography exposure at the exposure position, and the second workpiece stage performs silicon wafer loading and silicon wafer pre-alignment operations at the measurement position; the third step, after the pre-alignment of the second workpiece stage at the measurement position, the moving magnet The steel drive moves to the predetermined position A' of the measurement position and changes the stage and charges and waits. After the exposure of the first workpiece stage at the exposure position, the moving magnet steel drives and moves to the predetermined position C of the exposure position; the fourth step, the second workpiece stage and the first The workpiece table moves clockwise along the circular arc track through the vector control of the plane motor. When the second workpiece table is driven by the moving magnet to move to the predetermined position C of the exposure position, and the first workpiece table is driven by the moving magnet to move to the predetermined position D of the measurement position. , the stage change is over, the second workpiece stage at the exposure position enters the exposure state, and the first workpiece stage at the measurement position performs loading and unloading and pre-alignment operations. At this time, the system returns to the initial working state, and a job including two stage change operations is completed. The cycle is completed by wireless communication during the measurement, exposure and channel change process.

A moving magnet steel maglev double workpiece platform vector arc platform changing device based on spring damping, the device includes a support frame, a balance mass, a first workpiece platform, a second workpiece platform, and a wireless charging transmitter. The balance mass The block is located above the support frame, the stator of the macro-moving planar motor is installed on the plane on the balance mass block, the first workpiece table and the second workpiece table are arranged above the stator of the macro-moving planar motor, and the first workpiece table and the second workpiece table It runs between the measurement position and the exposure position, and the measurement position plane grating and the exposure position plane grating are respectively installed on the upper plane of the first work table and the second work table; the support frame is balanced by a motion compensation mechanism composed of four plane leaf springs. The mass blocks are connected, and the planar leaf spring is composed of 1 pair of X-direction leaf springs, 1 pair of Y-direction leaf springs, 1 Z-direction leaf spring and 1 Rz flexible hinge. The planar leaf springs are fixed on the support frame, and the planar leaf springs The sprung surface is connected with the balance mass block; the first workpiece table and the second workpiece table are six-degree-of-freedom maglev micro-motion tables, and the six-degree-of-freedom magnetic-flotation micro-motion tables are composed of Chuck, suction cups, micro-motion motors, anti-collision frames, macro The mover of the moving planar motor, the reading head of the planar grating, the leveling and focusing sensor, the wireless charging receiver, and the wireless communication transceiver are composed of the mover of the micro-moving planar motor and the mover of the gravity compensator. , the suction cup is installed on the Chuck, four planar grating reading heads and four leveling and focusing sensors are installed on the four corners of the Chuck, the Chuck is fixed on the micro-motor, and an anti-collision frame is installed around the micro-motor, The mover of the macro planar motor is installed under the anti-collision frame, the mover of the macro planar motor is composed of a magnetic steel array arranged in a staggered manner, and the stator of the macro planar motor is composed of a coil array arranged in a herringbone shape.

The present invention has the following innovations and outstanding advantages:

1) The proposed arc vector channel change scheme can effectively shorten the channel change time and improve the channel change efficiency. The vector table change strategy is used to optimize the existing multi-beat linear table change of the double workpiece table into a single-beat fast table change, with fewer starts and stops and fewer stable links; at the same time, the arc trajectory planning is used to shorten the table change path, and the rotary impact is small , The stable time is short, which is one of the innovative points and outstanding advantages of the present invention;

2) The proposed moving magnet steel maglev planar motor adopts compound current drive to realize high-efficiency vector control. It has the characteristics of large motion range, high thrust density, good dynamic characteristics, high winding utilization, uniform temperature distribution, and small thermal deformation. Using moving magnetic steel drive, wireless communication data transmission, no cable binding, simple structure, high positioning accuracy, this is the second innovation point and outstanding advantage of the present invention;

3) The proposed passive compensation mechanism based on planar leaf springs can realize the compensation of the X-direction, Y-direction, Z-direction, and Rz motion of the balance mass. Compared with the active compensation structure, the complexity of the mechanism is reduced, and the control and implementation Difficulty, this is the innovation point of the present invention and the third of outstanding advantages;

4) A work table exchange method without cable interference for wireless power supply and wireless communication is proposed, and a double work table device for wireless power supply and wireless communication is designed. Based on the maglev magnetic drive, the device adopts wireless power supply and wireless signal transmission methods to realize the wireless transmission and control of the power supply and communication signals of the two micro-tables, making the overall structure compact, and more importantly, eliminating the need for cables and signal lines The impact of cable disturbance on the positioning accuracy of the double worktable realizes wireless power supply, wireless communication data transmission and no cable constraints. This is innovation point and outstanding advantage four of the present invention.

Description of drawings

Fig. 1 is a schematic diagram of a single-beat optimized planning arc fast channel change process.

Fig. 2 is a schematic diagram of the overall structure of the moving magnet steel maglev double workpiece table vector arc table changing device based on spring damping.

Fig. 3 is a cross-sectional view of the dual stage system.

Fig. 4 is a schematic diagram of the assembly structure of the motion compensation mechanism and the balance mass.

Fig. 5 is a schematic diagram of the planar leaf spring structure.

Fig. 6 is a schematic structural diagram of a six-degree-of-freedom maglev micro-motion stage.

Fig. 7 is a schematic diagram of the integration mechanism of the micro-motion planar motor mover and the gravity compensator.

Fig. 8 is a schematic diagram of the arrangement of the magneto-rigid array of the macro-moving planar motor.

Fig. 9 is a schematic diagram of the arrangement of the stator coil array of the macro-motion planar motor.

Part number in the picture: 1-supporting frame; 2-balance mass system; 3-macro planar motor stator; 4a-first workpiece table; 4b-second workpiece table; 5a-measuring plane grating; 5b-exposure plane Grating; 11-measurement position; 12-exposure position; 13-parallel leaf spring; 26-X direction leaf spring; 27-Y direction leaf spring; 28-Z direction leaf spring; 29-Rz flexible hinge; 401-Chuck; 402 -suction cup; 403-micro motor; 404-anti-collision frame; 405-macro planar motor mover; 406-planar grating reading head; 407-leveling and focusing sensor; 408-micro planar motor mover; 409- Gravity compensator mover; 411-magnetic steel array; 412-coil array; 413-wireless charging receiver; 414-wireless communication transceiver.

detailed description

Below in conjunction with accompanying drawing, embodiment of the present invention is described in further detail:

A method for moving magnetic steel magnetic levitation double worktables based on spring damping and vector circular arc transfer, the method includes the following steps: in the initial working state, the first worktable at the measurement position is in the pre-aligned state, and the second workbench at the exposure position is in the Exposure state: the first step, after the pre-alignment of the first workpiece table at the measurement position, it is driven by the moving magnetic steel to move to the predetermined position A of the measurement position for changing the table, charging and waiting. Drive and move to the predetermined position C of the exposure position; in the second step, the first workpiece table and the second workpiece table move counterclockwise along the circular arc track through the vector control of the plane motor. During the movement, the phase of the two workpiece tables does not change. The moving position is measured by the plane grating. When the first workpiece table is driven by the moving magnetic steel to move to the predetermined position C of the exposure position, and the second workpiece table is driven by the moving magnetic steel to move to the predetermined position D of the measurement position, the stage change is completed, and the first The workpiece stage performs silicon wafer lithography exposure at the exposure position, and the second workpiece stage performs silicon wafer loading and silicon wafer pre-alignment operations at the measurement position; the third step, after the pre-alignment of the second workpiece stage at the measurement position, the moving magnet The steel drive moves to the predetermined position A' of the measurement position and changes the stage and charges and waits. After the exposure of the first workpiece stage at the exposure position, the moving magnet steel drives and moves to the predetermined position C of the exposure position; the fourth step, the second workpiece stage and the first The workpiece table moves clockwise along the circular arc track through the vector control of the plane motor. When the second workpiece table is driven by the moving magnet to move to the predetermined position C of the exposure position, and the first workpiece table is driven by the moving magnet to move to the predetermined position D of the measurement position. , the stage change is over, the second workpiece stage at the exposure position enters the exposure state, and the first workpiece stage at the measurement position performs loading and unloading and pre-alignment operations. At this time, the system returns to the initial working state, and a job including two stage change operations is completed. The cycle is completed by wireless communication during the measurement, exposure and channel change process.

A moving magnet steel magnetic levitation double workpiece table vector circular arc table changing device based on spring damping, the device includes a support frame 1, a balance mass 2, a first workpiece table 4a, a second workpiece table 4b, and a wireless charging transmitter 30 , the balance mass 2 is located above the support frame 1, the macro-motion planar motor stator 3 is installed on the plane on the balance mass 2, and the first work table 4a and the second work table 4b are arranged above the macro-motion planar motor stator 3 , the first workpiece table 4a and the second workpiece table 4b run between the measurement position 11 and the exposure position 12, and the measurement position plane grating 5a and the exposure plane grating 5a are respectively installed on the first workpiece table 4a and the second workpiece table 4b. The bit plane grating 5b; the support frame 1 is connected with the balance mass 2 through a motion compensation mechanism composed of four planar leaf springs 13, and the planar leaf spring 13 consists of a pair of X-direction leaf springs 26 and a pair of Y-direction leaf springs 27 , 1 Z-direction leaf spring 28 and 1 Rz flexible hinge 29, the planar leaf spring 13 is fixed on the support frame 1, and the upper surface of the planar leaf spring 13 is connected with the balance mass 2; the first workpiece table 4a and the second workpiece Table 4b is a six-degree-of-freedom maglev micro-motion stage, which consists of Chuck401, suction cup 402, micro-motion motor 403, anti-collision frame 404, macro-motion planar motor mover 405, planar grating reading head 406, It consists of a leveling and focusing sensor 407, a wireless charging receiver 413, and a wireless communication transceiver 414. The micro-motor 403 is composed of a micro-motion planar motor mover 408 and a gravity compensator mover 409. The suction cup 402 Installed on Chuck401, four planar grating reading heads 406 and four leveling and focusing sensors 407 are installed on the four corners of Chuck401, Chuck401 is fixed on the micro motor 403, and anti-collision frames 404 are installed around the micro motor 403 , the macro-moving planar motor mover 405 is installed under the anti-collision frame 404, the macro-moving planar motor mover 405 is composed of a magnetic steel array 411 arranged in a staggered manner, and the macro-moving planar motor stator 3 is composed of a coil array 412 arranged in a herringbone shape .

The working process of the present invention is as follows:

After the pre-alignment of the measurement position 11, the first workpiece table 4a is driven by the plane motor to move to the stage change position A, and waits for the second workpiece table 4b to complete the exposure at the exposure position 12. After the second workpiece table 4b completes the exposure, it is driven by the plane motor Drive and move to the stage change position B, and then the first workpiece table 4a and the second workpiece table 4b move counterclockwise along the circular arc track through the plane motor vector control to complete the stage change operation; after the stage change is completed, the first workpiece table 4a moves to the exposure position 12 moves to perform exposure at exposure position 12, and the second workpiece table 4b moves to measurement position 11 to perform loading and pre-alignment operations at measurement position 11; the second work table 4b that has completed pre-alignment of the silicon wafer first moves to the measurement position Change the stage position A', wait for the first workpiece stage 4a to complete the exposure and then move to the stage change position B', then, the second workpiece stage 4b and the first workpiece stage 4a move clockwise along the circular arc track through the vector control of the plane motor, and complete The second stage change; after the stage change is completed, the first workpiece stage 4a moves to the measurement position 11, and the second workpiece stage 4b moves to the exposure position 12, thus completing a complete working cycle.

Claims (2)

1. the dynamic magnet steel magnetic based on spring damping floats a double-workpiece-table vector circular arc channel switching method, it is characterized in that the method comprises the following steps: original operating state, measures position first work stage and is in prealignment state, and exposure position second workpiece platform is in exposure status, the first step, to measure after position first work stage prealignment by dynamic magnet steel actuation movement to measuring zapping precalculated position, position A and charging and waiting for, after the second workpiece platform exposure of exposure position by dynamic magnet steel actuation movement to exposing precalculated position, position C, second step, first work stage and second workpiece platform pass through planar motor vector controlled along arc track counterclockwise movement, in motion process, the phase place of two work stage does not change, movement position is measured by plane grating, when the first work stage is by moving magnet steel actuation movement to exposure precalculated position, position C, second workpiece platform by when moving magnet steel actuation movement to measurement precalculated position, position D, zapping terminates, first work stage carries out silicon chip photolithographic exposure in exposure position, and second workpiece platform carries out silicon chip upper slice and wafer pre-alignment operation in measurement position, 3rd step, to measure after position second workpiece platform prealignment by dynamic magnet steel actuation movement to measuring zapping precalculated position, position A' and charging and waiting for, after the work stage exposure of exposure position first by dynamic magnet steel actuation movement to exposing precalculated position, position C, 4th step, second workpiece platform and the first work stage pass through planar motor vector controlled along arc track clockwise movement, when second workpiece platform is by moving magnet steel actuation movement to exposure precalculated position, position C, first work stage is by when moving magnet steel actuation movement to measurement precalculated position, position D, zapping terminates, exposure position second workpiece platform enters exposure status, measure position first work stage and carry out fluctuating plate and prealignment operation, now system gets back to original operating state, complete the work period comprising twice zapping operation, in measurement, wireless communication mode is adopted to complete in exposure and zapping process.

2. the dynamic magnet steel magnetic based on spring damping floats double-workpiece-table vector circular arc programme changer, it is characterized in that this device comprises support frame (1), balance mass block (2), first work stage (4a), second workpiece platform (4b), wireless charging transmitter (30), described balance mass block (2) is positioned at support frame (1) top, grand dynamic planar motor stator (3) is arranged in the plane on balance mass block (2), first work stage (4a) and second workpiece platform (4b) are configured in grand dynamic planar motor stator (3) top, described first work stage (4a) and second workpiece platform (4b) run on to be measured between position (11) and exposure position (12), first work stage (4a) and the upper plane of second workpiece platform (4b) install and measure bit plane grating (5a) and exposure bit plane grating (5b) respectively, the motion compensation mechanism that support frame (1) consists of four planar chip springs (13) is connected with balance mass block (2), described planar chip spring (13) is made up of to sheet spring (26), 1 pair of Y-direction sheet spring (27), 1 Z-direction sheet spring (28) and 1 Rz flexible hinge (29) 1 couple of X, planar chip spring (13) is fixed on support frame (1), and planar chip spring (13) upper surface is connected with balance mass block (2), first work stage (4a) and second workpiece platform (4b) are six-freedom-degree magnetic suspension jiggle station, described six-freedom-degree magnetic suspension jiggle station is by Chuck(401), sucker (402), fine motion motor (403), crashproof frame (404), grand dynamic planar motor rotor (405), plane grating read head (406), leveling and focusing sensor (407), wireless charging receiver (413), wireless communication transceiver (414) forms, described fine motion motor (403) is integrated by fine motion planar motor rotor (408) and gravity compensator mover (409) and forms, described sucker (402) is arranged on Chuck(401) on, Chuck(401) four angles are provided with four plane grating read heads (406) and four leveling and focusing sensors (407), Chuck(401) be fixed on fine motion motor (403), in fine motion motor (403) surrounding, crashproof frame (404) is installed, described grand dynamic planar motor rotor (405) is arranged on crashproof frame (404) below, grand dynamic planar motor rotor (405) is formed by magnetic steel array (411) is staggered, grand dynamic planar motor stator (3) becomes herringbone arrangement to form by coil array (412).