JP5339729B2 - Stage apparatus and exposure apparatus having the same - Google Patents

Description

  The present invention relates to a stage apparatus and an exposure apparatus using the same.

  The exposure apparatus mounts an original (reticle or mask) and a substrate such as a wafer or a liquid crystal display on a dedicated stage device as a movable part, and exposes the pattern of the original on the substrate by driving and positioning the movable part. The stage device uses a linear motor, and it is necessary in terms of standards or safety to stop quickly when a power failure occurs, an emergency, a position measurement abnormality, or other abnormality occurs. However, if an excessive braking force or rotational force (yawing) is applied to the movable part during braking, the sliding part of the movable part may be damaged.

Therefore, in Patent Document 1, a limiting device that limits the current flowing through the coil is provided in a stage device that configures a closed circuit including a coil of a linear motor and operates a dynamic brake. The limiting means has a selector that selects a plurality of resistors having different resistance values and a resistor connected to the coil from among the resistors. The selector varies the current flowing through the coil in accordance with the position of the movable part.
Japanese Patent Laying-Open No. 2006-237069 (Claims 1, 4, paragraphs 0030-0034).

  As described above, Patent Document 1 changes the resistance value connected to the coil in accordance with the position of the movable portion in order to suppress the braking force and the rotational force of the stage device. However, in order to more effectively suppress the braking force and the rotational force according to various operating states of the stage device, there is room for improving the braking control of Patent Document 1.

  The present invention relates to a stage apparatus that can be stopped quickly and with low impact and low rotational force, and an exposure apparatus having the same.

A stage device according to one aspect of the present invention is a stage device that decelerates the movable part by moving a movable part by a linear motor and forming a closed circuit including at least one coil provided in the linear motor to apply a brake. in the in closed circuit and a plurality of resistors having different possible resistance connected to the coil, a speed detecting unit for detecting a moving speed of said movable portion, to connect or disconnect the pre-Symbol coil and said plurality of resistors A changeover switch and a first resistor that provides a first braking force when the speed detection unit detects a first speed as the moving speed of the movable part are selected from the plurality of resistances and connected to the coil. When the speed detector detects a second speed that is faster than the first speed as the moving speed of the movable part, the first braking force is smaller than the first braking force. Second resistor and having a control unit for controlling said selector switch to be connected to the coil is selected from the plurality of resistors to provide a braking force.

  According to the present invention, it is possible to provide a stage apparatus that can be stopped quickly and with low impact and low rotational force, and an exposure apparatus having the same.

  Hereinafter, a stage apparatus and an exposure apparatus having the same according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a plan view of the stage apparatus according to the first embodiment. The stage device is a stage device that moves a movable part by a linear motor, decelerates the movable part by forming a closed circuit including at least one coil included in the linear motor and applying a dynamic brake. The dynamic brake is a brake that applies a braking force by short-circuiting a terminal of the linear motor.

  The stage apparatus shown in FIG. 1 is an XY stage having a movable part 2 that moves in the Y direction and a movable part 6 that moves in the X direction, and the movable part can move two-dimensionally. Therefore, it is suitable for a stage for moving the substrate of the exposure apparatus, for example, a wafer stage described later. However, the present invention can also be applied to a stage that moves in a one-dimensional direction, and such a stage is suitable for a stage that moves an original plate of an exposure apparatus, for example, a reticle stage described later. Although any type of stage can move in the Z-axis direction, in this embodiment, focusing on the movement in a plane perpendicular to the Z direction (or the optical axis direction), the explanation of the movement in the Z direction is as follows. Omitted.

  On the surface plate (base) 1, the Y movable portion 2 is supported by the gas bearing 3. The gas bearing 3 supports the weight of the Y movable portion 2 and extends over a range in which the Y movable portion 2 moves in the Y-axis direction. The surface plate 1 is a rigid member that defines the XY plane and supports the main part of the stage apparatus. The Y movable unit 2 is a moving body that positions an object mounted thereon in the Y direction.

  A fixed magnet 4M (stator) of the movable coil type three-phase linear motor 4 is attached to the surface plate 1, and a plurality (two in this example) of movers 4C1 and 4C2 are attached to the movable part side. Further, the same three-phase linear motor 5 (stator 5M, movers 5C1, 5C2) is attached to the opposite side across the Y movable portion 2. The pair of fixed magnets 4M and 5M are rail members extending parallel to the Y direction, and guide the Y movable portion 2 in the Y direction. The linear motors 4 and 5 have a plurality of coils and magnets, and are so-called multiphase linear motors. In this embodiment, the stator is a magnet and the mover is a coil, but this may be reversed. The magnet has an N pole and an S pole, and a current is passed through a coil facing the magnet, thereby generating a Lorentz force and obtaining a thrust. The moving coil type three-phase linear motor 4 may be a moving coil type two-phase linear motor. Further, the number of movers of the three-phase linear motor 5 is not limited.

  The Y movable portion 2 is equipped with an X movable portion 6 that moves in a direction (X direction) orthogonal to the moving direction (Y direction) and an X movable portion motor 7 that drives the X movable portion 6. The X movable part 6 is a moving body that positions an object mounted on the X movable part 6 in the X direction. In addition, the structure of the motor 7 is not specifically limited, A linear motor like patent document 1 may be sufficient.

  A laser interferometer 8 for measuring the position in the X direction and a laser interferometer 9 for measuring the position in the Y direction are fixed on the surface plate 1. Further, on the movable portion 6, a mirror 10 for measuring the position in the X direction and a mirror 11 for measuring the position in the Y direction are provided. The mirror 10 is a bar mirror that reflects the measurement light emitted from the laser interferometer 8 in the −X direction on the reflection surface, and the mirror 11 reflects the measurement light emitted from the laser interferometer 9 in the + Y direction on the reflection surface. It is a bar mirror. The laser interferometer 8 and the mirror 10 function as a position detection unit that detects the position of the X movable unit 6 in the X direction. The laser interferometer 9 and the mirror 11 function as a speed detection unit that detects the moving speed of the Y movable unit 2 in the Y direction. The detection results by the laser interferometers 8 and 9 are sent to the host controller 12 described later. As will be described later, since the host controller 12 calculates the moving speed of the Y movable unit 4 and the position (or thrust ratio) of the X movable unit 6, the host controller 12 is used as a position detection unit and a speed detection unit. You may think including it.

  FIG. 3 is a control block diagram of the Y movable unit 2.

  The host controller 12 controls the driving of the movable parts 2 and 6 based on the detection results by the laser interferometers 8 and 9 and the target value. Specifically, the current flowing through the coils of the linear motors 4 and 5 is controlled (position control / speed control / acceleration control / synchronous control), and the operation of the motor 7 is controlled.

  The power supply rack 13 includes a power supply controller 14, motor power supplies 15 to 18, a brake controller (control unit) 19, brake circuits 20 to 23, and a backup power supply 24. Since the brake circuits 21 to 23 have the same configuration as that of the brake circuit 20, the following description will be focused on the brake circuit 20.

  The brake circuit 20 includes a brake main switch 25, a resistor 26 having a plurality of resistors R1, R2, and R3, and a changeover switch 27. When the brake main switch 25 is closed, a closed circuit for short-circuiting the coils 4C1U (U phase), 4C1V (V phase), and 4C1W (W phase) in the mover 4C1 is formed.

  The brake main switch 25 functions as a closed circuit configuration switch that forms a closed circuit including coils 4C1U (U phase), 4C1V (V phase), and 4C1W (W phase). The opening and closing of the brake main switch 25 is controlled by the brake controller 19.

  In this embodiment, three resistors R1, R2 and R3 are provided in the resistor 26, but the present invention does not limit the number of resistors. The plurality of resistors R1, R2, and R3 can be connected to the coils 4C1U (U phase), 4C1V (V phase), and 4C1W (W phase) in the closed circuit, and have different resistance values. In this embodiment, the relationship of R1 <R2 <R3 is established, but the present invention is not limited to this. By placing the resistor 26 in the closed circuit, the back electromotive force generated in the mover coil during braking can be consumed as thermal energy by the resistor 26 to reduce the braking force. The brake circuit 20 can be configured in the power supply 15 or can be configured outside the power supply rack 13.

  The changeover switch 27 connects or disconnects the coil and the plurality of resistors R1 to R3 based on the detection results of the laser interferometers 8 and 9. That is, the changeover switch 27 connects any one of the plurality of resistors R1 to R3 to the corresponding coil, or does not connect any of the resistors to the corresponding coil. Details of the operation of the changeover switch 27 will be described later with reference to Table 1.

  When the stage device is operating normally, the brake release signal 28A is given from the host controller 12 to the brake controller 19, and the brake main switch 25 is opened, and the closed circuit is not formed, so that the brake does not work. Next, a current command 29 for the linear motor 4 and a current command 30 for the linear motor 5 are given from the host controller 12 to the power supply controller 14. Thus, current is supplied from the power sources 15 to 18 to the movable elements 4C1, 4C2, 5C1, and 5C2, and the Y movable part 2 is driven.

  The host controller 12 calculates the current moving speed 31 of the Y movable unit 2 from the current position of the laser interferometer 9. Further, the position of the center of gravity of the Y movable portion in the X direction (6a shown in FIG. 2) is obtained from the current position of the laser interferometer 8, and two pieces of force are applied to prevent the rotational force (yawing) from acting on the Y movable portion. The linear motor thrust ratio 32 is calculated. The host controller 12 transmits the moving speed 31 and the thrust ratio 32 to the brake controller 19. The thrust ratio 32 indicates the ratio of the thrust of the linear motor 4 to the total thrust.

  The brake circuits 20 to 23 are activated when a power failure occurs or when an abnormality occurs in the laser interferometer 9. Even during a power failure, the brake controller 19 can be operated by the backup power supply 24 of the power supply rack 13, and the brake can be operated until the Y movable part 2 stops. Further, the past movement speed 31 and the thrust ratio 32 are stored in the storage unit 33 in the brake controller 19 for a certain period of time. As a result, even when a power failure occurs or the laser interferometer is abnormal, the contents of the storage unit 33 can be recognized as the current state (moving speed 31, thrust ratio 32) and the brake can be applied. The storage unit 33 can be composed of an EEROM or the like.

  During the brake operation, first, a brake signal 28B is transmitted to the brake controller 19. The brake controller 19 operates the changeover switch 27 according to the moving speed 31 and the thrust ratio 32 to select one of the resistors R1 to R3 and closes the brake main switch 25. The same operation is performed for the brake circuits 21 to 23. As a result, the brake works, and the Y movable portion 2 decelerates and stops.

  The brake controller 19 stores in advance a brake setting 34 (an open / close state of a brake main switch in the brake circuits 20, 21, 22, and 23, a setting of a resistance changeover switch) for an assumed moving speed and an assumed thrust ratio. Stored in the unit 33. The brake setting 34 may be stored in the storage unit in the host controller 12 or other places.

  Table 1 is an example of the brake setting 34. The moving speed 31 is a moving speed of the Y movable unit 2 in the Y direction. For example, “1” indicates a low speed, “2” indicates a medium speed, and “3” indicates a high speed. The thrust ratio 32 represents the position of the X movable part 6 in the X direction. For example, “30” represents the left side in FIG. 1, “50” represents the center, and “70” represents the right side as shown in FIG. Sw1 represents the brake main switch 25, and Sw2 represents the changeover switch 27. “-” Indicates that no resistance is selected. When Sw1 is OFF, the brake circuit does not work.

  The resistance connected to each brake circuit can be obtained from the necessary braking force, the thrust ratio of the linear motor, the weight of the Y movable part 2, the moving speed 31, and the thrust ratio 32. According to the brake setting 34, the resistance is selected in each brake circuit and the brake is applied. Therefore, regardless of the moving speed, the brake can be applied with a braking force close to a desired value.

  In Patent Document 1, the resistance is selected considering only the thrust ratio 32 (or the position of the X movable portion 6), and the moving speed of the Y movable portion 2 is not considered. However, if the moving speed is low, the braking force applied to the sliding part of the movable part during braking is small, and if the moving speed is high, the braking force applied to the sliding part of the movable part during braking is large. In this embodiment, the resistance is selected in consideration of such a difference in braking force.

  When a resistor having a small resistance value is selected, a larger braking force remains because heat consumption by the resistor is small. Further, when a resistor having a large resistance value is selected, the heat consumption by the resistor is large, so that the braking force becomes smaller.

  Since the braking force is small when the moving speed 31 is low (“1”), for example, when the X movable portion 6 is in the center (“50”), the resistance R1 is selected to secure the braking force. It aims at quick braking. On the other hand, when the moving speed 31 is high (“3”), the braking force is large, and if a large braking force is left, the sliding portion of the movable part may be damaged. Therefore, for example, when the X movable portion 6 is in the center (“50”), the resistance R2 larger than the resistance R1 is selected to reduce the braking force and ensure safety.

  Further, as shown in FIG. 2, when the center of gravity position 6 a of the Y movable portion 2 is deviated from the center position of the two stators 4M and 5M, the linear motor 4 and the linear motor 5 differ according to the thrust ratio 32. A resistance can be selected. Thereby, a difference can be provided in the braking force of two linear motors, and the rotational force (yawing) which acts on the Y movable part 2 at the time of a brake can be suppressed. For example, when the moving speed 31 is high (“3”) and the thrust ratio is rightward (“70”) as shown in FIG. 2, the resistor R3 is connected to the coil 4C1, and the resistor R3 is connected to the coil 5C1. Connected. In addition, no resistance is connected to the coils 4C2 and 5C2. However, this is merely an example, and the coils connected to the resistors in the left and right stators 4M and 5M may be diagonal pairs (for example, a pair of coils 4C1 and 5C2).

  FIG. 4 is a control block diagram of the Y movable unit 2 according to the second embodiment.

  In the second embodiment, a function capable of repeatedly opening and closing the brake main switch 25 is added to the configuration of the first embodiment within a certain time (control cycle). The opening / closing time of the brake main switch 25 sets an opening time To and a closing time Tc within a certain fixed time (control cycle) T. The brake controller 19 controls the timing for opening and closing the brake main switch 25.

  During the brake operation, first, the brake signal 28B is transmitted to the brake controller 19. The brake controller 19 selects a resistor to be connected by operating the changeover switch 27 according to the moving speed. The brake controller 19 selects a necessary opening / closing time of the brake main switch 25 according to the moving speed 31 and the thrust ratio 32, and repeats opening / closing of the brake main switch 25. The same operation is performed for the brake circuits 21, 22, and 23. As a result, the brake works, and the Y movable portion 2 decelerates and stops.

  The brake controller 19 stores in advance a brake setting 34 (setting of the changeover switch 27 in each brake circuit 20 to 23 and opening / closing time of the brake main switch 25) for an assumed moving speed and an assumed thrust ratio. Save to 33.

  Table 2 is an example of the brake setting 34. The moving speed 31 is a moving speed of the Y movable unit 2 in the Y direction. For example, “1” indicates a low speed, “2” indicates a medium speed, and “3” indicates a high speed. The thrust ratio 32 represents the position of the X movable part 6 in the X direction. For example, “30” represents the left side in FIG. 1, “50” represents the center, and “70” represents the right side as shown in FIG. Sw1 represents the brake main switch 25, and Sw2 represents the changeover switch 27. T is a control cycle (switching cycle), and Tc is a closing time of the brake main switch 25 within the control cycle T. The resistance connected to each brake circuit can be determined from the necessary braking force, the linear motor thrust ratio 32, the weight of the Y movable portion 2, and the moving speed 31.

  In Table 2, unlike Table 1, the resistor R1 is selected when the moving speed is low (“1”), the resistor R2 is selected when the moving speed is medium (“2”), and the high speed (“3”) is selected. ), The resistor R3 is selected. Thus, in this embodiment, the resistance selected by the changeover switch 27 according to the moving speed is fixed. However, this is merely an example, and resistance may be distinguished according to the thrust ratio 32 as shown in Table 1.

  By adding the continuous opening / closing function of the brake main switch 25 to the control of the braking force only by the resistor (Example 1), the control performance of the braking force can be enhanced as compared with Example 1, and the desired braking force The brake can be applied with a braking force closer to.

  As shown in FIG. 2, when the center of gravity position 6 a of the Y movable portion 2 is deviated from the center position of the two linear motors, the brake main switch is switched between the linear motor 4 and the linear motor 5 according to the thrust ratio 32. The opening / closing time of is set differently. Thereby, a difference can be provided in the braking force of two linear motors, and the rotational force (yawing) which acts on the Y movable part 2 at the time of a brake can be suppressed.

  Even when a power failure, an emergency stop, or other abnormality occurs, the stage device of Examples 1 and 2 applies a brake to decelerate and stop the stage regardless of the moving speed of the movable part at that time. be able to. This reduces the possibility of damage to the stage apparatus. In the case where the linear motors are arranged in two pairs with the movable part interposed therebetween, it is possible to apply the brake by changing the braking force acting on the two linear motors according to the position of the center of gravity of the movable part. For this reason, the rotational force (yawing) which acts on a movable part can be suppressed. As a result, the possibility of damage to the stage apparatus is reduced.

  Hereinafter, an exposure apparatus to which the above-described stage apparatus can be applied will be described. As shown in FIG. 5, the exposure apparatus 500 includes an illumination apparatus 501, a reticle stage 502 on which a reticle is mounted, a projection optical system 503, and a wafer stage 504 on which a wafer is mounted. Reference numeral 510 denotes a surface plate, which corresponds to the surface plate 1 in FIGS. 3 and 4. The exposure apparatus exposes the reticle pattern onto the wafer. Although the exposure apparatus of this embodiment uses a step-and-repeat method, the present invention allows the exposure apparatus to use a step-and-scan method.

The illumination device 501 illuminates a reticle on which a circuit pattern is formed, and includes a light source unit and an illumination optical system. The light source unit uses, for example, a laser or a mercury lamp as a light source. As the laser, an ArF excimer laser with a wavelength of about 193 nm, a KrF excimer laser with a wavelength of about 248 nm, an F ₂ laser with a wavelength of about 153 nm, or the like is used. The illumination optical system is an optical system that illuminates the mask, and includes a lens, a mirror, a light integrator, a diaphragm, and the like.

  The projection optical system 503 uses a refractive optical system, a catadioptric optical system (catadioptric optical system), a reflective optical system, and the like, and projects a reticle pattern onto the wafer.

  The stage apparatus according to the first or second embodiment can be applied to the reticle stage 502 and the wafer stage 504. Thereby, an exposure apparatus with high safety and reliability can be provided. When applied to the reticle stage 502, as described above, for example, it moves only in the Y direction. In this case, in Tables 1 and 2, the thrust ratio 32 is fixed at 50, for example.

  Next, an embodiment of a device manufacturing method using the above-described exposure apparatus 500 will be described with reference to FIGS. Here, FIG. 6 is a flowchart for explaining the manufacture of a semiconductor device (a semiconductor chip such as an IC or LSI, or a liquid crystal panel or a CCD sensor).

  In step 1 (circuit design), a semiconductor device circuit is designed. In step 2 (reticle fabrication), a reticle on which the designed circuit pattern is formed is fabricated. On the other hand, in step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the prepared reticle and wafer. The next step 5 (assembly) is called a post-process, and is a process for forming a semiconductor chip using the wafer produced in step 4, and is a process such as an assembly process (dicing, bonding), a packaging process (chip encapsulation), or the like. including. In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. Through these steps, the semiconductor device is completed and shipped (step 7).

  FIG. 7 is a detailed flowchart of the wafer process in Step 4 shown in FIG. In step 11 (oxidation), the surface of the wafer is oxidized. In step 12 (CVD), an insulating film is formed on the wafer surface. In step 13 (electrode formation), an electrode is formed on the wafer by vapor deposition or the like. In step 14 (ion implantation), ions are implanted into the wafer. In step 15 (resist process), a photosensitive material is applied to the wafer. Step 16 (exposure) uses the exposure apparatus 500 to expose a circuit pattern on the mask onto the wafer. In step 17 (development), the exposed wafer is developed. In step 18 (etching), portions other than the developed resist image are removed. In step 19 (resist stripping), the resist that has become unnecessary after the etching is removed.

  By repeatedly performing these steps, multiple circuit patterns are formed on the wafer. In the manufacturing method of this embodiment, the safety and reliability of manufacturing are improved as compared with the prior art by providing a stage device that can be stopped quickly and with low impact and low rotational force to the reticle stage or wafer stage.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist.

FIG. 3 is a plan view of the stage device according to the first embodiment. It is a top view which shows a mode that the X movable part shown in FIG. 1 moved to the right side. It is a control block diagram of the Y movable part of the stage apparatus shown in FIG. It is a control block diagram of the Y movable part of the stage apparatus of Example 2. It is sectional drawing of the exposure apparatus which can apply the stage apparatus of Example 1 or 2. 6 is a flowchart of a device manufacturing method using the exposure apparatus shown in FIG. It is a flowchart for demonstrating the detail of step 4 shown in FIG.

Explanation of symbols

2 Y movable part / linear motor 4C1, 4C2, 5C1, 5C2 Mover 4C1U to W Coil 6 X movable part 8 Laser interferometer (position detection part)
9 Laser interferometer (speed detector)
12 Host controller 19 Brake controller (control unit)
25 Brake main switch (closed circuit configuration switch)
26 Resistor 27 selector switch 33 Memory section R1, R2, R3 Resistance

Claims (7)

In the stage device that moves the movable part by a linear motor, decelerates the movable part by configuring a closed circuit including at least one coil provided in the linear motor and applying a brake,
A plurality of resistors having different resistance values connectable to the coil in the closed circuit;
A speed detector for detecting a moving speed of the movable part;
A changeover switch for connecting or disconnecting the plurality of resistors with the previous SL coil,
When the speed detection unit detects a first speed as the moving speed of the movable part, a first resistance that provides a first braking force is selected from the plurality of resistances and connected to the coil, and the speed detection When the second part detects a second speed that is faster than the first speed as the moving speed of the movable part, a second resistance that provides a second braking force that is smaller than the first braking force is the plurality of resistances. A control unit that controls the changeover switch so as to be selected from a resistor and connected to the coil;
A stage apparatus characterized by comprising: A position detection unit that detects a position of the movable unit in a direction orthogonal to the moving direction of the movable unit detected by the speed detection unit;
The stage device is provided with two linear motors for moving the movable part,
When the position of the center of gravity of the movable part detected by the position detection part deviates from the center position in the direction orthogonal to the moving direction of the movable part, the control part passes two linear motors via the changeover switch. The stage apparatus according to claim 1 , wherein a difference is provided between the braking forces of the two linear motors so as to suppress a rotational force acting on the movable part more than when the braking forces of the two linear motors are equal . Further comprising a closed circuit configuration switch that constitutes the closed circuit and is repeatedly opened and closed while decelerating the movable part ,
Wherein the control unit, the stage apparatus according to claim 1, wherein the benzalkonium control the timing for opening and closing the closed circuit configuration switches. A position detection unit that detects a position of the movable unit in a direction orthogonal to the moving direction of the movable unit detected by the speed detection unit;
The stage device is provided with two linear motors for moving the movable part,
When the position of the center of gravity of the movable part detected by the position detector deviates from the center position in the direction orthogonal to the moving direction of the movable part, the control unit passes two closed circuit configuration switches. 4. The stage apparatus according to claim 3, wherein a difference is provided in the opening / closing timings of the two linear motors so as to suppress the rotational force acting on the movable part as compared with the case where the braking forces of the linear motors are equal. A position detection unit that detects a position of the movable unit in a direction orthogonal to the moving direction of the movable unit detected by the speed detection unit ;
A storage unit for storing the speed and the position of the movable unit;
Further comprising
Wherein, based on said speed and said position of said movable portion to which the storage unit is stored, according to claim 1, wherein the changeover switch and controls so as to select one of said plurality of resistors 5. The stage apparatus according to any one of 4 to 4 . An exposure apparatus that exposes a pattern of an original on a substrate using light from a light source,
Exposure apparatus characterized by driving the original or the substrate by using a stage apparatus according to any one of claims 1 to 5. Exposing the substrate using the exposure apparatus according to claim 6 ;
Developing the exposed substrate;
A device manufacturing method comprising: