JP2002112526A - Flat motor, stage-positioning system, and aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact motor that has a simple coil array, consisting of dense coils and realizes six degrees of freedom at a high speed, with accuracy and high energy efficiency. SOLUTION: A flat electric motor is provided with a magnet array, that produces magnetic fields whose polarity alternates and a coil array that is adjacent to the magnet array and is placed, to that the coil array and the magnetic fields interact with each other, and electromagnetic force is produced between the coil array and the magnet array. The coil array comprises a first linear coil array, including a plurality of coils formed in a polygon longer than is wide in a first direction, and a second linear coil array including a plurality of coils formed in an ellipse longer than is wide in a second direction which is substantially orthogonal with the first direction. The motor is used to move a stage, and the stage supports an optical system for forming the pattern of a reticle on an object in an aligner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor, and more particularly, to a high precision motor for a lithography system.

[0002]

2. Description of the Related Art Many precision systems, such as those used in semiconductor manufacturing, use linear or planar motors to position objects such as semiconductor wafers. Conventional planar motors are disclosed in U.S. Pat.
Nos. 654,571, 5,196,745, and 5,334,892.

[0003]

These patents describe planar motors with significant limitations. For example, the planar motor of US Pat. No. 3,851,196
Exercise range is restricted. This is because each part of the fixed magnet array generates a force in only one direction. Therefore, each coil array must be located on the magnet array. This limits the range of motion for a given size actuator. Similarly, the motor disclosed in U.S. Pat. No. 5,196,745 is such that each coil array is linear.
Must be located on the magnet array. The motor of U.S. Pat. No. 4,654,571 has a coil design that produces only a limited force due to the layout of the coils on the stage. Furthermore, the design does not generate forces of six degrees of freedom. US Patent No. 5,33
The planar motor disclosed in U.S. Pat. No. 4,892, has a wide range of motion, but is limited to one plane.

[0004] In the prior art, the stacking arrangement is difficult to handle for the purpose of achieving six degrees of freedom of movement. Such a stacked arrangement requires extra power, reduces positioning accuracy, etc.
Has some challenges. Regardless of the stacking arrangement, a motor that provides six degrees of freedom in the entire range of motion of the wafer stage would require a large magnet and coil to provide the desired force for a typical planar motor. This results in a larger overall stage and system, resulting in lower natural frequencies and lower performance.

In addition, conventional systems often involve the complicated geometry of the coil, which can lead to an increase in the size of the motor or the entire stage, thereby increasing the required power. The complex geometry of the coils often hinders the compaction of the coils, and also increases and increases the size and efficiency of the motor. Also, the coil array requires many coils and amplifiers, as well as complex electrical controls to excite the coils and drive the motor.

[0006] Thus, there is a need for a compact motor having an uncomplicated coil array of dense coils that provides high speed and high precision with six degrees of freedom and high energy efficiency.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems by a compact motor having coils of a simple geometric shape and providing six degrees of freedom and high energy efficiency.

A planar motor according to the present invention includes a magnet array for generating a magnetic field having alternately reversed polarities, and an electromagnetic force adjacent to and adjacent to the magnet array. A coil array arranged to interact with the magnetic field. A first linear coil array having a plurality of coils formed in a polygon elongated in a first direction;
And a second linear coil array having a plurality of coils formed in an elongated oval in a second direction substantially orthogonal to the first direction. Preferably, each of the elliptical coils has a length greater than the length of the polygonal coil and is substantially flat with substantially flat upper and lower surfaces. The magnet may have, for example, a rectangular or octagonal cross-sectional shape. The magnets may be arranged in a checkerboard pattern in which the polarity alternates between rows and columns, in which case the magnets
For example, one row has magnets of the same polarity, and adjacent rows all have magnets of the opposite polarity. The magnets may be clustered or spaced from one another.

A planar motor according to the present invention has a magnet array having a plurality of magnets for generating magnetic fields having alternately reversed polarities, and an electromagnetic force adjacent to the magnet array and between the magnet array and the magnet array. A coil array arranged to interact with said magnetic field to generate. The coil array includes a first coil having a plurality of first coils formed in an oblong shape elongated in a first direction.
And a plurality of second coils formed in a vertically elongated ellipse in a second direction orthogonal to the first direction. The magnet may have, for example, a rectangular or octagonal cross-sectional shape. The magnets may be arranged in a checkerboard pattern in which the polarity alternates between rows and columns.In this case, for example, the magnets may have magnets in which all rows have the same polarity and adjacent rows have magnets of the same polarity. All have magnets of opposite polarity.

An exposure apparatus according to the present invention mainly includes a frame, an optical system mounted on the frame and forming an image on an object, and a base disposed below the optical system. A stage for supporting and positioning the object is located adjacent to the base. This device also
An electric motor capable of moving the stage is provided. The motor is capable of interacting with the magnetic field so as to generate a magnetic field having a magnetic field having an alternately inverted polarity, and an electromagnetic force adjacent to the magnet array and between the magnet array. And a coil array arranged at The coil array includes a first linear coil array having a plurality of coils formed in a polygon elongated in a first direction, and an oblong elongated in a second direction substantially orthogonal to the first direction. A second linear coil array having a plurality of coils formed therein. The stage so that one of the magnet array and the coil array moves with the stage relative to the other of the magnet array and the coil array connected to the base. It is connected to the.

An exposure apparatus according to the present invention mainly includes a frame, an optical system mounted on the frame, for transferring a pattern formed on a reticle onto an object, and a base disposed below the optical system. . A stage for supporting and positioning the object is positioned adjacent the base. The apparatus further includes an electric motor capable of moving the stage. The electric motor, a magnet array having a plurality of magnets that generate a magnetic field with a polarity that is alternately reversed, and adjacent to the magnet array, to generate an electromagnetic force between the magnet array, A coil array arranged to interact with the magnetic field. The coil array includes a first linear coil array having a plurality of first coils formed in an oblong shape that is vertically elongated in a first direction, and a first linear coil array that is elongated in a second direction substantially orthogonal to the first direction. A second linear coil array having a plurality of second coils formed in an oblong shape; One of the coil array and the magnet array is connected to the stage so as to move with the stage relative to the other of the magnet array and the coil array connected to the base. Have been.

A stage positioning system according to the present invention includes a stage movable relative to a stationary base in a first direction and a second direction orthogonal to the first direction, and an electric motor capable of moving the stage. Prepare for the subject. The electric motor interacts with the magnetic field so as to generate an electromagnetic force between the magnet array and a magnet array that generates a magnetic field with an alternately reversed polarity. It comprises a coil array that can be arranged. The coil array includes the first
A first linear device having a plurality of first coils vertically elongated in a direction
A coil array, and a second linear coil array having a plurality of second coils elongated in the second direction. The second coil has a length that exceeds a length of the stage in the second direction. One of the magnet array and the coil array is connected to the base and the magnet array and the coil array.
The stage is connected to move with the stage relative to the other of the arrays.

The above description addresses some of the problems of the prior art,
And a brief description of the advantages of the present invention. Other features, advantages, and embodiments of the invention will be apparent to one skilled in the art from the following description, figures, and claims.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Note that the same portions are denoted by the same reference symbols throughout the drawings. First, in FIG. 1, the electric motor of the present invention is indicated by reference numeral 20, and is shown together with a stage 22 to which the motor is attached. The stage 22 to which the motor is attached is for positioning a semiconductor wafer (not shown) in a photolithography process. Electric motor 20 is also used in other types of positioning systems for positioning reticles in semiconductor processing and for positioning objects other than semiconductor wafers. The electric motor 20 includes a magnet array 24 and a reference numeral 26.
3 is a planar motor including the coil array shown in FIGS. 1 and 2. The motor 20 has an electromagnetic force (Lorentz force)
Is used to propel the stage 22. The magnet array 24 is disposed adjacent to the coil array 26 and provides a permanent magnetic field that interacts with the current distribution in the coil array to create a force between the magnet array and the coil array. The interaction of the magnetic field with the current distribution allows one of the magnet array 24 and the coil array 26 to move relative to the other in at least three degrees of freedom, preferably six degrees of freedom. For example, coil
The current in the array 26 interacts with the magnetic field from the magnet array 24 to produce x, y, and z forces and x, y,
and torque about the y and z axes.
For a discussion of these interactions and the general operation of planar motors, see Hazelton et al., November 16, 1998.
U.S. patent application Ser. No. 09 / 192,813 and Hazelton's U.S. patent application Ser.
/ 135,624. The entire text of the aforementioned U.S. patent application is incorporated herein by reference.

As shown in FIG. 1, the magnet array 2
4 is mounted on a stage 22 and is free to move with the stage relative to a stationary coil array 24. Such a moving magnet embodiment is preferable to a moving coil arrangement when used to position a device because the magnet array 24 does not require a current connection. In addition, if cooling of the coils is required, cooling tubes (not shown) must be attached to the coil array 26. Electrical connections and cooling tubes can interfere with the movement of the coil array 26. However, for other purposes,
The array 26 may be movable relative to the fixed magnet array mounted on the stage 22.

Referring now to FIGS. 3 (a) -5, the interaction between the coil array 26 and the magnet array 24 is shown, and more specifically, the movement in the x, y, and z directions. , The commutation of the coil array providing torque around the x and y axes, and rotational movement about the z axis.
3A to 5 show the embodiment of the motor 20 in which the coil moves, the following description can be applied to the embodiment in which the magnet moves. The magnet array 24 includes a plurality of magnets 38 (three shown in the figure) mounted on the magnetic plate 28. Magnet 38
Alternates the polarity in the z-direction. coil·
Array 26 is shown above magnet array 24 and has three wires 30, 3 connected to a single-phase current source.
2 and 34 are schematically shown. For simplicity, only three coil wires are shown in FIGS. 3 (a) and 4 (a). As is well known to those skilled in the art, coil array 26 includes a large number of dense wires connected to a rectifier circuit having multiple phases (eg, two or three phases). In this case, each phase includes multiple wires.

The wires 30, 32, 34 are magnet
It is located just above the magnet 30 of the array 24. A rectifier circuit (not shown) controls and supplies current to wires 30,32,34. The filled points on the wire are
The current flowing out of the plane of the drawing in the −y direction is shown, and the x-shape on the wire shows the current flowing in the + y direction of the drawing.
As shown in FIG. 3 (a), the currents on wires 30 and 34 flow into the plane of the figure, and the currents on wire 32 flow out of the plane of the figure. The dashed line indicates the magnetic flux passing through the magnet array 24, and the arrow on the magnet 38 indicates the magnetic polarity. According to Lorentz's law, the electromagnetic force acts on the coil array 26 only in the + x direction. The electromagnetic force acting on the magnet array 24 in the opposite direction with the same magnitude balances each component of the electromagnetic force acting on the coil array 26. Wires 30, 32, 3 of coil array 26
As 4 moves laterally relative to magnets 38 of magnet array 25, current Ix eventually falls to zero.

FIG. 3B shows the current Ix as a function of the position of the coil array 26 along the x-axis. The current Ix is used to obtain the force and movement of the coil array 26 relative to the magnet array 24 in the x direction. The current Ix is supplied by a rectifier circuit, typically in a sinusoidal waveform, as clearly shown in FIG. 3 (b) being aligned with the planar motor of FIG. 3 (a).

FIG. 4A shows the motor 20 of FIG. 3A, wherein the coil array 26 has adjacent wires 32,3.
4 shows the state after propulsion of a distance equal to approximately half the distance between the four. At this time, the wires 32 and 34 are located between the respective magnets 38. The rectifier circuit is
Current is supplied to flow out of the plane of the drawing of the wires 30 and 34 in the -y direction and to flow in the + y direction of the drawing plane of the wire 32. The electromagnetic force acting on the coil array 26 generated according to Lorentz's law acts on the coil array 26 only in the + z direction. The component force in the z direction acts to promote the floating of the coil array 26 from the magnet array 24. The magnitude of the current is determined by the coil array 26 on the magnet array 24.
Adjust the height of the. The relative tilt angle of the coil array 26 with respect to the magnet array 24 can be adjusted by supplying different amounts of current to different wires. For example, by supplying a stronger current to the wire 32 than the wire 34, the right side of the coil array 26 (in the direction of viewing FIG. 4A) on the magnet array 24 is positioned on the left side of the coil array. Rising higher. This gives the coil array 26 rotational movement about the y-axis. As can be clearly seen in FIG. 4 (b), which is aligned with the planar motor of FIG. 4 (a), the wires 30, 32, 34 cause each magnet 3
When moving just beyond 8, the current Iz falls to zero.

As shown on the wire 34 in FIGS. 3A and 4A, the Lorentz force causes the z-component that promotes the floating of the coil array 26 from the magnet array 24, and the z-component of the coil component. It has an x component that urges in the x direction. x
When only a directional force is desired, the z direction component is canceled by the opposite z force on the wire. This opposite z-force is commutated by reversing the different phases and either the magnetic flux or the current to the wire 34.
This leaves only the force in the x direction.

The levitating magnets 42 and 44 are used to help the coil array 26 (FIG. 4A) (or the magnet array 24) levitate. The magnets 42 and 44 serve as a means for floating the stage 22, and
It is also used to increase the rectification of directional forces. As a result, the current required to generate a force in the z direction for floating the stage 22 is reduced.

FIG. 5 shows a motor 20, which has six wires A1, A2, B distributed in three different phases A, B, C, where the two wires are of the same phase.
1, B2, C1, and C2. Each magnet 38
The polarity of the
The magnetic flux paths of the array 26 are indicated by dashed lines. Opposite currents flow through pairs of wires of the same phase. Because
Because these wires are part of one continuous current loop. Thus, wires A1, B1, and C1 contain currents in opposite directions from wires A2, B2, and C2, respectively. According to Lorentz's law, the electromagnetic force on the wires A1, A2, B1, B2, C1, and C2 acts in the direction indicated by the arrow coming out of each wire. The electromagnetic force on the wires A1, A2 in phase A acts only in the x direction. The wires B1, C1, B2, C2 of the phases B and C are:
All have the z component of the electromagnetic force. The + z component acting on the phase C wires C1 and C2 is the phase B wire B1
And B2 acting on B2 in the same way, leaving only the net component on the coil array 26 in the x direction. For other commutation configurations, the component in the x direction is similarly canceled between the phases, leaving only the net component in the z direction.

Several examples of rectifying configurations have been described. As is well known to those skilled in the art, motion and force in the x, y, and z directions, torque around the z axis, torque around the x, y, and z axes, and around the x, y, and z axes. Many other commutation configurations can be applied to the coils to provide rotation. As can be seen, other portions of the coil array also differ from those shown in FIGS. 3 (a) -5 in order to produce different amounts of x and z force in different portions of the electric motor 20. Similarly, it is rectified by a current or current distribution. Motor 20
Is divided in the x and y directions,
Rotational forces around the x, y and z axes, linear forces in the x and z directions are generated. The equalization of the forces acting on the coils distributed in the y direction provides a rotational force about the x axis and a linear force in the y and z directions. Thus, six degrees of freedom of the operation of the electric motor 20 are achieved.

As shown in FIG. 2, the coil array has x
An x-linear coil array (x-coil array) 50 for moving the stage along the axis and a y-linear coil array (y-coil array) for moving the stage along the y-axis 52. The current rectified in two phases, three phases, or multiple phases by a rectifier circuit and a current source (not shown) to apply a force in the x direction to the stage 22 relative to the coil array 26,
Provided to x-coil array 50 in a conventional manner (FIGS. 1 and 2). Each rectifier circuit and current source provides a two-phase, three-phase, or multi-phase rectified current to the y-coil array 52 to apply a y-axis force to the stage 22. A rectified current is applied to coils 54 in x-coil array 50 to impart rotation to stage 22 relative to coil array 26 in an xy plane parallel to the x and y axes. , Supplied individually. Alternatively, current may be supplied to all coils 54 of x-coil array 50 individually, but of opposite polarity. In this case, one coil is supplied with force in one direction and the other coil is supplied with force in the opposite direction, thereby generating a torque around the z-axis. The rectifier circuit and current source are controlled by a conventional motor controller (not shown) that provides logic signals that guide the operation of the motor.

The x-coil array 50 is oriented such that the coils 54 are major axes in a direction perpendicular to the x axis, and y
The coil array 52 is oriented such that the coil 56 is the major axis in a direction perpendicular to the y-axis. In operation, each coil 54, 56 produces a substantially constant force along each of the x or y directions. To generate a force in the y-direction, a coil 56 placed directly under the magnet array 24 and stage 22 is energized. Similarly, a coil 54 positioned directly below the magnet array 24 and stage 22 is energized to produce a force in the x-direction.

The x-coil array 50 includes a plurality of hexagonally formed coils 54 (FIGS. 2 and 6 (a)).
(B)). The mechanism and the configuration method of the coil 54 are as follows.
U.S. patent application Ser. No. 09/059, Apr. 10, 998;
No. 056. The entire text of the aforementioned U.S. patent application is incorporated herein by reference. Each coil 54 includes opposed legs, each having one long portion 60 and two short portions 62. The long part 60 is
They extend substantially parallel to one another and are spaced apart from one another. Each of the shorts 62 extends at an angle from the long 60 and the free ends of the shorts merge with each other to form a central opening 68.
Is formed (FIG. 6A). The length of the legs 60, for example, in order to rectify the motor to a three-phase, preferably spaced a distance twice the width W _L of the legs. The coil 54 is formed from a plurality of wires (e.g., 7 or 8) (not shown) that are in close contact with each other to form the legs of the coil. Preferably, the wire is copper and has a circular cross-sectional shape. As shown in FIG. 6B, the coil 54
The legs of the coil are bent so that they are substantially in the same plane. Due to the limitation on the bending radius of the wire, small bumps 58 are formed at each end of the coil 54.

In addition to the hexagonal coil 54 shown in FIGS. 6A and 6B, other polygons including a diamond shape, a double diamond shape, a parallelogram and the like may be used. Further, the coil 54 may be oval. FIG. 7 and FIG.
A plurality of diamond shaped coils 70 are shown arranged to form x-coil arrays 51,53. To construct the x-coil arrays 51, 53,
As shown in FIG. 7, first, rows 72 of coils 70 having partial overlap are assembled parallel to the vertical axis A. The row 72 includes six sets 73 of coils 70. Each set 73 includes two coils 70 for each of the three phases.
The number of coils 70 in a row may vary, and is determined by the phase of the motor 20 and the choice for each phase. Each phase of one row 72 is driven by a separate amplifier in a rectifier circuit (not shown). The x-coil arrays 51, 53 each include a plurality of rows 72. FIG. 7 is an example of an array of rows 72 by coils 70 and an x-coil array 51.
Are arranged side by side on a non-colinear line in the horizontal direction with respect to the vertical axis A forming. The rows 72 are preferably arranged in a direction substantially orthogonal to the vertical axis A. FIG. 8 shows another arrangement of rows 72, arranged side-by-side with partial overlap, thereby providing x-coil coils with partial overlap in the lateral direction.
An array 53 is formed. Row 72 is preferably the length of the stage plus the mileage required for the stage.

The y-coil array 52 comprises a plurality of coils 56 wound in an approximately oval (FIG. 2). Coil 5
6 is composed of a plurality of wires having a circular or rectangular cross section. The elliptical coil 56 can also be formed using laminated flex circuit technology. Stacked flex circuits consist of stacks that include layers of a flexible circuit board. Each layer of the stack
It includes an insulating material (preferably polyimide) and a conductive material (preferably copper). These layers can be formed, for example, by overlaying copper on a polyimide base. Each layer is
It includes a single swirl structure made of a conductive material, or a spiral structure including several swirl structures made of a conductive material. Holes are formed in the insulating material to electrically connect adjacent layers. Since the coil 56 does not have the acute angle of the polygonal coil 54, the coil does not have a protrusion at the end of the coil. Thus, the elliptical coil 56 is substantially flat with substantially flat upper and lower surfaces. Thereby, the coils 54 are densely arranged without being separated from each other. Further, since the end 75 of the elliptical coil 56 has a shorter length than the short portion 62 (the portion forming the end of the coil 54), most of the length produces a force, Improve motor performance. The oval coil 56 is formed with opposing legs 74 disposed adjacent to each other, and defines an opening 76 in the center of the coil.

The length Lcy of the coil 54 is
Is preferably equal to or less than about half the length Lsy in the y direction (FIG. 1). Length Lcx of coil 56
Is preferably slightly longer than the length obtained by adding the length Lsx of the stage in the x direction to the stroke in the x direction of the motor. Therefore, the length Lcx of the coil 56 is
Is preferably at least twice the length Lcy. The width Wc of the coil 56 is preferably substantially equal to the magnet pitch Mp of the magnet array 24. Since the elliptical coil 56 is longer than the polygonal coil 54, the number of required elliptical coils 56 is smaller than that of the polygonal coil 54. As a result, the total number of amplifiers for the motor 20 can be reduced as compared with a conventional motor having a coil array.

The y-linear coil array is stacked vertically on the x-linear coil array in the z direction (perpendicular to the x and y axes (FIG. 2)). Of course, unless it goes beyond the scope of the present invention, the coil array 26
May have a different sequence from that shown above. For example, the x and y-coil arrays 50, 52 may be replaced so that the x-coil array is superimposed on the y-coil array. The x and y-coil arrays 50, 52
For example, it is mounted on a magnetically permeable panel (not shown) made of a material such as iron. The permeable panel is a coil 5
4 and 56, the permanent magnetic flux is increased, and the performance of the motor 20 is improved.

FIG. 9 shows another embodiment of the coil array. In the example of FIG. 9, only two phases are used for the motor 20 to reduce the number of coils and amplifiers. As shown in FIG. 9, the coil array is an x linear coil array (x
A coil array) 50 and a y-linear coil array (y-coil array) 52 for moving the stage along the y-axis. The current rectified in two phases by a rectifier circuit and a current source (not shown) to apply a force in the x direction to the stage 22 relative to the coil array 26, in a conventional manner, x− Coil array 50
Supplied to In order to apply a force in the y-axis direction to the stage 22, a current rectified in two phases is supplied to the y-coil array 52 by each rectifier circuit and a current source. The rectified current is applied to the coils 5 in the x-coil array 50 to impart rotation to the stage 22 relative to the coil array 26 in an xy plane parallel to the x and y axes.
4, or coil 56 in y-coil array 52
Are supplied individually. Alternatively, the current can be expressed as x
All coils 54, 56 of either the -coil array 50 or the y-coil array 52 may be supplied individually, but of opposite polarity. In this case, one coil is supplied with force in one direction and the other coil is supplied with force in the opposite direction, thereby generating a torque around the z-axis. The rectifier circuit and current source are controlled by a conventional motor controller (not shown) that provides logic signals that guide the operation of the motor. In this case, other rectification configurations can be applied. For example, a three-phase or multi-phase current can also be applied.

The x-coil array 50 is oriented such that the coils 54 are major axes in a direction perpendicular to the x axis, and y
The coil array 52 is oriented such that the coil 56 is the major axis in a direction perpendicular to the y-axis. Coil 54
Are arranged to provide a thrust in the x direction, and the coils 5
6 are arranged to provide a thrust in the y-direction.
To generate a force in the y-direction, a magnet array 24
And the coil 56 placed just below the stage 22 is excited. Similarly, a coil 54 positioned directly below the magnet array 24 and stage 22 is energized to produce a force in the x-direction. To provide a rotation parallel to the xy plane, certain coils 54, 56 or coil array 5
Either 0, 52 or both the x and y-coil arrays are selectively energized.

The x-coil array 50 and the y-coil array
Each of the arrays 52 individually has a plurality of coils 54,5.
6 inclusive. As shown in FIG. 9, the coils 54 and 56 are windings formed in an oval. The coils 54 and 56 are formed of a plurality of closely wound copper wires (not shown), and preferably have a circular or rectangular cross-sectional shape. The elliptical coils 54 and 56 can also be formed using a laminated flex circuit technique. Stacked flex circuits consist of stacks that include layers of a flexible circuit board. Each layer of the stack includes an insulating material (preferably polyimide) and a conductive material (preferably copper). These layers can be formed, for example, by overlaying copper on a polyimide base. Each layer includes a single spiral structure made of a conductive material, or a spiral structure including several spiral structures made of a conductive material. Holes are formed in the insulating material to electrically connect adjacent layers.

The oval coils 54, 56 are substantially flat with substantially flat upper and lower surfaces. Thereby, the coil 5
4,56 do not separate from each other and are dense. Oval coil 5
4,56 are formed with opposing legs 74 located adjacent to each other, where there is only one narrow slit passing through the coil. This provides substantially continuous flat upper and lower surfaces. The ratio of the length Lc of the coils 54 and 57 to the width Wc of the coil is preferably at least 2.0, and more preferably at least 2.5. The x and y coils 54, 56 are preferably of the same size and shape, but may be different from each other. For example, the x-coil 54, the y-coil 56, or both the x and y-coils may be formed in an oval shape with the legs 74 separated so as to form an opening in the center of the coil (not shown). .

Each of the x and y-coil arrays 50, 52 is arranged laterally such that the coils 54, 56 form one row, the rows being close together, thereby forming an array structure. . x linear coil array 50
Is then in the z direction (perpendicular to the x and y axes (FIG. 9))
And vertically stacked on the y-linear coil array 52. Each of the x and y-coil arrays 50,52 includes two stacked rows of coils 54,56. The layers of two stacked coils 54,56 in each coil array 50,52 provide two phases of power (i.e., one layer of coils provides one phase). The horizontal pitch between the layers is Wc / (2 × number of phases). Thus, it is preferable to use only two phases in order to reduce the number of coils and amplifiers.

Of course, without departing from the scope of the present invention, the coil array 26 may be arranged differently than previously shown. For example, x and y-coils
Arrays 50, 52 may be a checkerboard pattern consisting of a plurality of squares, where x and y-coil arrays 50, 52 are arranged adjacent to one another and are stacked in one layer rather than stacked on one another. There may be. In the checkerboard array, the alternating squares are x and y coils 54, 56 having orthogonal directions.
including. The x and y-coil arrays 50 and 52 are mounted on a magnetically permeable panel (not shown) made of a material such as iron. The permeable panel is composed of coils 54 and 5
6, the permanent magnetic flux is increased, and the performance of the motor 20 is improved.

FIG. 10 shows a first embodiment of the magnet array 24. The magnet array includes a plurality of magnets 38, wherein the plurality of magnets 38 comprises x
Arranged in a first direction along the axis and in a second direction along the y-axis to form a two-dimensional magnet array. The magnets 38 are arranged in two directions along the x and y axes in a staggered checkerboard arrangement. The pole of the magnet 39 has z in the direction of inflow or outflow in the plane of the drawing.
An orientation is defined along the axis (ie, north pole or south pole). The polarity of the magnet 38 alternates between adjacent rows and columns. For example, one line is all N
It has a pole magnet 38, and all rows adjacent to it have an S pole magnet. Of course, the arrangement of the magnets 38 and the types of magnets may be different from those shown above without departing from the scope of the present invention. For example, the magnets 38 may be closely aligned with one another without gaps, or the orientation of the poles may be determined along each row or column. If the magnets are arranged closely together, the magnet array will have x and y coils 54,
Preferably, it is oriented at an angle of 45 ° to 56.

A second embodiment of the magnet array is shown in FIG. Magnet array 80
Includes a plurality of octagonal magnets 82, and the plurality of magnets 82 are arranged in two directions. The magnets 82 are evenly separated from each other, and alternate in polarity between adjacent rows and columns.

FIG. 12 shows a third embodiment of the magnet array, designated by the numeral 84. The magnet array 84 comprises two linear magnet sets 86 having rectangular magnets aligned parallel to the y-axis;
Two linear magnet sets 87 having rectangular magnets aligned parallel to the x-axis (perpendicular to the y-axis)
Is provided.

The magnet array is, for example, 1998
The wedge magnet described in Hazelton et al., U.S. Patent Application Serial No. 09 / 168,694, dated October 5, may be used.

FIG. 13 schematically shows an example of an exposure apparatus 90. This exposure apparatus uses the electric motor 20 of the present invention. The exposure apparatus mainly includes a frame 88, an optical system, a motor 20, and a stage 22 that supports and positions the wafer W. The optical system is mounted on a frame 88 above a base 92. Although the base 92 is shown connected to the frame 88, it may be located separately from the frame. The coil array 26 is mounted on the upper surface of the base 92. The magnet array 24 is connected to the lower surface of the stage 22,
It is relatively movable with respect to the coil array 26 and the optical system. The optical system includes a mask formed on the reticle R
Patterns (eg, circuit patterns for semiconductor devices)
Emit light to Reticle R is reticle stage RS
Supported and scanned by T. The optical system is a light source LMP
And an elliptical mirror EM surrounding the light source. The illuminating device includes an optical integrator FEL for producing a secondary light source image, and a condenser lens CL for illuminating the reticle R with a uniform light flux. The projection lens group PL focuses light on the wafer W. The wafer W is positioned below the projection lens group PL, and is preferably held on a wafer holder (not shown) supported on the wafer stage 22 by vacuum suction. In operation, the beam from the illuminator is
To expose the photoresist on the wafer W. The wafer W is supported and scanned by a stage 22 driven by a motor 20. A more detailed configuration of the exposure apparatus 90 is described in, for example, Lee, US Patent No. 5,528,11.
No. 8 may be referred to. Naturally, the present invention is not limited to the above-described exposure apparatus 90 or an exposure system for processing a wafer. The exposure apparatus 90 referred to above is merely an example of one embodiment in which the present invention is used.

From the above, the object of the present invention is achieved and other favorable results are obtained. Within the scope of the present invention, various changes can be made to the above configuration and method, and all matters described above and shown in the accompanying drawings are
It goes without saying that this is interpreted as an example and is not limited to this.

In addition to the above photolithography system,
The present invention is directed to a scanning type photolithography system that exposes a mask pattern while the mask and substrate move synchronously (see, for example, US Pat.
No. 3,410). Further, the present invention provides a step-and-repeat type photolithography system as a photolithography system according to the present embodiment, in which a mask pattern is exposed while a mask and a substrate are fixed, and the substrate is moved in continuous steps. Also applicable to The entire text of US Pat. No. 5,473,410 is incorporated herein by reference.

Further, according to the present invention, as a photolithography system according to the present embodiment, a mask and a substrate are set close to each other without using a projection optical system.
The present invention is also applicable to a proximity photolithography system that exposes a mask pattern.

The use of a photolithography system
The present invention is not limited to semiconductor manufacturing, but can be widely applied to other applications. For example, the present invention can be applied to an LCD photolithography system for exposing a liquid crystal display pattern on a rectangular glass substrate and a photolithography system for manufacturing a thin film magnetic head.

The light source for the photolithography system of the present invention will be described. The g-line (436 nm), the i-line (365 nm), and the KrF excimer laser (248n)
m), ArF excimer laser (193 nm), and F
Not only _two lasers (157 nm) but also a charged particle beam such as an X-ray and an electron beam may be used. For example, when an electron beam is used, a thermionic emission type lanthanum hexaboride (La) is used as an electron gun.
B ₆ ) or tantalum (Ta) can be used. further,
When an electron beam is used, a structure using a mask may be used, or a pattern may be formed directly on a substrate without using a mask.

Regarding the magnification of the projection optical system, not only the reduction system but also any of the same magnification and the enlargement system may be used. Further, when far ultraviolet rays such as an excimer laser are used as the projection optical system, a material that transmits the far ultraviolet rays such as quartz or fluorite is used as the glass material. When an F ₂ laser or X-ray is used, a catadioptric system or It is preferable to use a reflection type reticle as the optical system of the system, and to use an electron beam as an optical system including an electron lens and a deflector when an electron beam is used. It goes without saying that the optical path through which the electron beam passes is set in a vacuum state.

When a linear motor (see US Pat. No. 5,623,853 or US Pat. No. 5,528,118) is used for a wafer stage or a reticle stage,
Either an air levitation type using an air bearing or a magnetic levitation type using Lorentz force or reactance force may be used. The stage may be of a type that moves along a guide or a guideless type that does not have a guide. U.S. Patent Nos. 5,623,853 and 5,528,118 are incorporated herein by reference in their entirety.

The reaction force generated by the movement of the wafer stage is disclosed in Japanese Patent Application Laid-Open No. 8-166475 (US Pat.
28, 118), a frame member may be used to mechanically escape to the floor (ground). The entire text of US Pat. No. 5,528,118 is incorporated herein by reference.

The reaction force generated by the movement of the reticle stage can be measured mechanically by using a frame member as described in JP-A-8-330224 (US Patent Application No. 08 / 416,658). (Earth). The entire text of US patent application Ser. No. 08 / 416,658 is:
The description is incorporated herein by reference.

As described above, the photolithography system according to the present embodiment is capable of converting various subsystems including the components described in the claims of the present application into predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Manufactured by assembling to maintain accuracy. Before and after this assembly, adjustments to achieve optical accuracy for various optical systems, adjustments to achieve mechanical accuracy for various mechanical systems, and various electric systems to ensure these various accuracy Are adjusted to achieve electrical accuracy. The process of assembling the various subsystems into the photolithography system includes mechanical connections, wiring connections of electric circuits, and piping connections of pneumatic circuits among the various subsystems. From these various subsystems, photolithography and
It goes without saying that there is an individual assembly process for each subsystem before the assembly process for the system. When the process of assembling the various subsystems into the photolithography system is completed, a total adjustment is performed to ensure various accuracy of the entire photolithography system. It is desirable that the manufacture of the exposure system be performed in a clean room in which temperature, cleanliness, and the like are controlled.

The semiconductor device is, as shown in FIG.
Step 201 for designing the function and performance of the device, Step 202 for manufacturing a mask (reticle) based on this design step, Step 203 for manufacturing a wafer from a silicon material, and the pattern of the reticle by the photolithography system of the above-described embodiment. The wafer is manufactured through a wafer processing step 204 of exposing the wafer to a wafer, a device assembling step (including a dicing step, a bonding step, and a package step) 205, an inspection step 206, and the like. Then, the devices that pass the inspection are delivered to the appropriate customers.

[0053]

According to the present invention, it is possible to provide a motor which is a compact motor having an uncomplicated coil array composed of dense coils and which provides high-speed and high-precision six degrees of freedom and high energy efficiency.

[Brief description of the drawings]

FIG. 1 is a perspective view of an electric motor according to the present invention, showing a state where a magnet array of the motor is mounted on a stage.

FIG. 2 is a plan view of a coil array according to the present invention.

3A is a diagram schematically showing the interaction between a magnet array and a coil array in the electric motor of the present invention, and FIG. 3B is a diagram illustrating a component of an electromagnetic force in the electric motor of FIG. FIG.

FIG. 4 (a) schematically shows the electric motor of FIG. 3 (a), and shows how the coil array has moved relative to the magnet array from the position of FIG. 3 (a). FIG. 4B is a diagram for explaining the component force of the electromagnetic force in the electric motor of FIG.

FIG. 5 is a view showing an electric motor of the present invention having a three-phase rectifying structure.

6 (a) is a perspective view of one coil of the coil array of FIG. 1, and FIG. 6 (b) is a side view of the coil of FIG. 6 (a).

FIG. 7 is a plan view showing a row of coils.

FIG. 8 is a plan view showing a changed arrangement of rows and columns in FIG. 7;

FIG. 9 is a perspective view of an electric motor according to the present invention, showing a magnet array mounted on a stage and arranged above a coil array, which is partially cut away for detailed explanation.

FIG. 10 is a perspective view of the magnet array of FIG. 1;

FIG. 11 is a plan view of a second embodiment of the magnet array of FIG. 10;

FIG. 12 is a plan view of a third embodiment of the magnet array of FIG. 10;

FIG. 13 is a view showing an exposure apparatus using the electric motor of FIG. 1;

FIG. 14 is a flowchart showing a semiconductor device manufacturing process according to the present invention.

[Explanation of symbols]

 W Wafer R Reticle PL Projection lens group 20 Planar motor 22 Stage 24 Magnet array 26 Coil array 30, 32, 34 Wire 38 Magnet 50 x Linear coil array 52 y Linear coil array 54 Coil 56 Coil 88 Frame 90 Exposure equipment 92 base

Claims (68)

[Claims] 1. A magnet array for generating a magnetic field with an alternately inverted polarity, and capable of interacting with the magnetic field so as to generate an electromagnetic force between the magnet array and the adjacent magnet array. A first linear coil array having a plurality of coils formed in a polygon elongated in a first direction, and a coil array substantially arranged in the first direction. A second linear linear motor having a plurality of coils formed in a vertically long oval in a second direction orthogonal to the first linear motor;
A planar motor comprising a coil array. 2. The planar motor according to claim 1, wherein each of the elliptical coils has a length that exceeds a length of the polygonal coil. 3. The planar motor of claim 2, wherein the ratio of the length of the oval coil to the length of the polygonal coil is at least about 2. 4. The planar motor according to claim 1, wherein each of the plurality of elliptical coils has a length that exceeds a required moving distance of the planar motor in the second direction. 5. The planar motor of claim 1, wherein each of the plurality of oblong coils is substantially flat with substantially flat upper and lower surfaces. 6. The planar motor of claim 1, wherein the elliptical coils are stacked in an array having a partial overlap in the first direction to form one row of coils. Planar motor. 7. The planar motor according to claim 1, wherein the polygon is a hexagon. 8. The planar motor according to claim 1, wherein the polygonal coils are arranged in an adjacent arrangement in the second direction to form one row of polygonal coils. motor. 9. The planar motor of claim 1, wherein the polygonal coils are arranged in an arrangement having a partial overlap in the second direction to form one row of polygonal coils. Is a planar motor. 10. The planar motor according to claim 1, wherein the plurality of elliptical coils include fewer coils than the plurality of polygonal coils. 11. The planar motor according to claim 1, wherein one of the magnet array and the coil array is six free relative to the other of the magnet array and the coil array. A planar motor that can move in degrees. 12. The planar motor according to claim 1, wherein the magnet array has magnets two-dimensionally arranged so as to have alternately different polarities in adjacent rows and columns. 13. The planar motor according to claim 1, wherein the magnet array includes a plurality of the magnets. 14. The planar motor according to claim 13, wherein each of the plurality of magnets has a rectangular cross-sectional shape. 15. The planar motor according to claim 13, wherein each of the plurality of magnets has an octagonal cross-sectional shape. 16. The planar motor according to claim 1, wherein the plurality of elliptical coils are stacked on the plurality of polygonal coils. 17. An array of magnets for generating a magnetic field with alternately reversed polarities, and capable of interacting with the magnetic field so as to generate an electromagnetic force between the magnet array and the adjacent magnet array. A first linear coil having a plurality of first coils formed in an oblong shape elongated in a first direction.
A planar motor comprising: an array; and a second linear coil array having a plurality of second coils formed in an oblong shape elongated in a second direction substantially orthogonal to the first direction. 18. The planar motor according to claim 17, wherein the first linear coil array is stacked on the second linear coil array. 19. The planar motor according to claim 17, wherein each of the plurality of first and second coils has a continuous flat lower surface and a continuous flat upper surface substantially parallel to the lower surface. A planar motor having a motor. 20. The planar motor according to claim 17, wherein each of the plurality of first and second coils has a ratio of a length in a longitudinal direction to a lateral direction of the ellipse is at least 2. . 21. The planar motor according to claim 17, wherein the first and second coils are arranged in an array adjacent in the lateral direction so as to form a plurality of rows of the first and second coils. Is a planar motor. 22. The planar motor according to claim 21, wherein the rows of the first and second coils are in close contact with each other. 23. The planar motor according to claim 17, wherein the first coil has a different shape and size from the second coil. 24. The planar motor according to claim 17, wherein the magnet array has a plurality of magnets two-dimensionally arranged so as to have alternately different polarities in adjacent rows and columns. motor. 25. The planar motor according to claim 24, wherein the magnet array has a plurality of the magnets two-dimensionally spaced apart from each other. 26. The planar motor according to claim 25, wherein each of the plurality of magnets has a rectangular cross-sectional shape. 27. The planar motor according to claim 25, wherein each of the plurality of magnets has an octagonal cross-sectional shape. 28. The planar motor according to claim 17, wherein the magnet array and the coil array are arranged in the first direction, the second direction, the first direction, and the second direction.
A planar motor capable of generating a force in a third direction substantially orthogonal to the direction. 29. The planar motor according to claim 28, wherein the magnet array and the coil array generate a torque that relatively rotates the magnet array and the coil array around the third direction. A planar motor that can be generated. 30. The planar motor according to claim 29, wherein the magnet array and the coil array relatively move the magnet array and the coil array around the first direction and the second direction. A flat motor that can generate torque to rotate the motor. 31. A frame, an optical system mounted on the frame and forming an image on an object, a base disposed below the optical system, and a base disposed adjacent to the base, A stage configured to support an object, the stage and the optical system being relatively movable, and an electric motor being capable of moving the stage, wherein the electric motor generates a magnetic field having alternately reversed polarities. A magnet array to be generated, and a coil array adjacent to the magnet array and arranged to interact with the magnetic field so as to generate an electromagnetic force between the magnet array and the coil. The array is the first
A first linear coil array having a plurality of coils formed in a polygon that is vertically elongated in a direction, and a plurality of coils formed in an elongated oval in a second direction substantially orthogonal to the first direction; A second linear coil array, wherein one of the magnet array and the coil array is connected to the base, and the other of the magnet array and the coil array is connected to the base with respect to the base. And an exposure apparatus connected to the stage so as to relatively move with the stage. 32. The exposure apparatus according to claim 31, wherein each of the elliptical coils has a length that exceeds a length of the polygonal coil. 33. The exposure apparatus according to claim 32, wherein a ratio of a length of the oval coil to a length of the polygonal coil is at least about 2. 34. The exposure apparatus according to claim 31, wherein each of the elliptical coils has a length that exceeds a required moving distance of the planar motor in the second direction. 35. The exposure apparatus according to claim 31, wherein each of the plurality of oblong coils is substantially flat with substantially flat upper and lower surfaces. 36. The exposure apparatus according to claim 31, wherein the elliptical coils are stacked in an array having a partial overlap in the first direction to form one row of coils. Exposure equipment. 37. The exposure apparatus according to claim 31, wherein the polygonal coils are arranged in an adjacent arrangement in the second direction to form one row of polygonal coils. apparatus. 38. The exposure apparatus according to claim 31, wherein the polygon is a hexagon. 39. The exposure apparatus according to claim 31, wherein the plurality of elliptical coils include fewer coils than the plurality of polygonal coils. 40. The exposure apparatus according to claim 31, wherein one of the magnet array and the coil array is six free relative to the other of the magnet array and the coil array. An exposure device that can be moved in degrees. 41. The exposure apparatus according to claim 31, wherein the plurality of oval coils are stacked on the plurality of polygonal coils. 42. The exposure apparatus according to claim 31, wherein the magnet array is connected to a lower surface of the stage so as to move with the stage, and the coil array is connected to an upper surface of the base. Exposure equipment. 43. The exposure apparatus according to claim 31, wherein the magnet array includes a plurality of magnets. 44. A frame, an optical system mounted on the frame, for transferring a pattern formed on a reticle onto an object, a base disposed below the optical system, and supporting and positioning the object. A stage movable adjacent to the base and the optical system, and an electric motor capable of moving the stage, wherein the electric motor is alternately inverted. A magnet array that generates a magnetic field according to polarity, and a coil array that is adjacent to the magnet array and that is arranged to interact with the magnetic field so as to generate an electromagnetic force between the magnet array. Wherein the coil array comprises a first
A first linear coil array having a plurality of first coils formed in a vertically elongated ellipse in a direction; and a plurality of first linear coils formed in a vertically elongated oval substantially perpendicular to the first direction. A second linear coil array having two coils, wherein one of the coil array and the magnet array is connected to the base,
An exposure apparatus, wherein the other of the array and the coil array is connected to the stage so as to move with the stage relative to the base. 45. The exposure apparatus according to claim 44, wherein the first linear coil array is stacked on the second linear coil array. 46. The exposure apparatus according to claim 44, wherein each of the plurality of first and second coils has a continuous flat lower surface and a continuous flat upper surface substantially parallel to the lower surface. Exposure apparatus. 47. The exposure apparatus according to claim 44, wherein each of the plurality of first and second coils has a ratio of a length in a longitudinal direction to a shorter direction of the ellipse is at least 2. . 48. The exposure apparatus according to claim 44, wherein the first and second coils are arranged adjacent to each other in the short direction so as to form a plurality of rows by the first and second coils. Exposure equipment to be arranged. 49. The exposure apparatus according to claim 48, wherein the rows of the first and second coils are close to each other. 50. The exposure apparatus according to claim 44, wherein the first coil has a different shape and size from the second coil. 51. The exposure apparatus according to claim 44, wherein the magnet array has a plurality of magnets two-dimensionally arranged so as to have alternately different polarities in adjacent rows and columns. Exposure equipment. 52. The exposure apparatus according to claim 51, wherein the magnet array has a plurality of magnets two-dimensionally arranged apart from each other. 53. The exposure apparatus according to claim 52, wherein each of the plurality of magnets has a rectangular cross-sectional shape. 54. The exposure apparatus according to claim 52, wherein each of the plurality of magnets has an octagonal cross-sectional shape. 55. The exposure apparatus according to claim 44, wherein the magnet array and the coil array are substantially perpendicular to the first direction, the second direction, and the first and second directions. An exposure apparatus capable of generating forces in three directions. 56. The exposure apparatus according to claim 55, wherein the magnet array and the coil array generate torque for relatively rotating the magnet array and the coil array around the third direction. Exposure equipment that can be generated. 57. The exposure apparatus according to claim 56, wherein the magnet array and the coil array relatively rotate the coil array and the magnet array around the first and second directions. An exposure apparatus that can generate a torque to be applied. 58. The exposure apparatus according to claim 44, wherein the coil array is connected to the base, and the magnet array moves with the stage relative to the base and the coil array. An exposure apparatus connected to the stage so that 59. A stage, comprising: a stage movable in a first direction and a second direction orthogonal to the first direction relative to a stationary base; and an electric motor capable of moving the stage. The electric motor is capable of interacting with the magnetic field so as to generate an electromagnetic force between the magnet array and a magnet array that generates a magnetic field having a polarity that is alternately inverted and adjacent to the magnet array. A first linear coil array having a plurality of first coils that are vertically elongated in the first direction, and a plurality of first linear coil arrays that are vertically elongated in the second direction. A second linear coil array having two coils, each of said second coils having a length greater than a length of said stage in said second direction; A stage positioning system, wherein one of the array and the coil array is connected to the stage to move with the stage relative to the other of the magnet array and the coil array. 60. The stage positioning system according to claim 59, wherein the first coil has a polygonal shape. 61. The stage positioning system according to claim 59, wherein the second coil has an oval shape. 62. The stage positioning system according to claim 59, wherein a length of the first coil is about half a length of the stage in a first direction. 63. The stage positioning system according to claim 59, wherein the length of the second coil is a length obtained by adding a required moving distance of the motor in the second direction to a length of the stage in a second direction. Stage positioning system that exceeds the standard. 64. The stage positioning system according to claim 59, wherein the second coils are stacked in an array having an overlap in the first direction. 65. The stage positioning system according to claim 59, wherein said magnet array is connected to said stage. 66. The stage positioning system according to claim 59, wherein the magnet array comprises a plurality of magnets. 67. A stage, comprising: a stage movable relative to a stationary base in a first direction and a second direction orthogonal to the first direction; and an electric motor capable of moving the stage. The electric motor is capable of interacting with the magnetic field so as to generate an electromagnetic force between the magnet array and a magnet array that generates a magnetic field with alternately reversed polarities. A first linear coil array having a plurality of first coils vertically elongated in the first direction, and a plurality of first linear coil arrays vertically elongated in the second direction. A second linear coil array having two coils, each of said second coils having a length at least twice as long as said first coil; Stage positioning, wherein one of the magnetic array and the coil array is connected to the stage so as to move with the stage relative to the other of the magnet array and the coil array. system. 68. The stage positioning system according to claim 67, wherein the magnet array includes a plurality of magnets for generating the magnetic field.