JPH10223527A - Aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate adverse effect on the positioning accuracy of cable by controlling the moving amount such that a constant relative positional relationship is kept between a substrate stage and an interconnecting means for moving cables, connected fixedly with a substrate stage movable along the upper surface of a base, in the same direction. SOLUTION: A main control system supplies a drive signal simultaneously to a substrate stage drive system through a stage control system and to a robot arm 50 so that a cable relaying section 51 follows up the movement of a substrate stage 15. The relaying section 51 secured with cables 41 moves two-dimensionally in XY coordinate system while following up the movement of the substrate stage such that relative position to the substrate stage 15 is not varied. Since the cables 41 extending from the substrate stage 15 can sustain a same shape regardless of the fact that the stage 15 is located in the center of a base 17 or shifted to upper right part or lower left part and thereby the positioning accuracy is not degraded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus for manufacturing a semiconductor device or a liquid crystal display device, and more particularly to an XY stage in the exposure apparatus.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices and liquid crystal display devices, an exposure apparatus is used to expose a pattern of a reticle or a mask (hereinafter, referred to as a mask) to a photosensitive substrate such as a semiconductor wafer or a glass plate. The exposure apparatus includes a stage device having a substrate stage movable in two-dimensional X and Y directions as means for moving the photosensitive substrate to a predetermined exposure position.

FIG. 9 is a conceptual diagram of a conventional stage device. A substrate stage 71 having a substrate mounting surface on an upper side is driven by a driving unit along a base 72 in an XY direction (not shown).
It moves freely in the two-dimensional direction above. The photosensitive substrate is mounted on the substrate mounting surface of the substrate stage 71, and is held by vacuum suction by evacuating a vacuum suction hole (not shown) provided on the substrate mounting surface. As this type of stage moving mechanism, a technique disclosed in Japanese Patent Application Laid-Open No. 58-175,020 can be used.

The substrate stage 71 includes a cable for supplying power to driving means such as a motor disposed inside the substrate stage, a cooling liquid pipe for cooling the motor, and a cooling liquid for maintaining the substrate stage at a predetermined temperature. A pipe, a vacuum pipe for evacuating a vacuum suction hole provided on the substrate mounting surface, and the like (hereinafter, these cables and pipes are collectively referred to as cables) are connected. These cables 73 are fixed to a fixed portion 73a of the substrate stage 71 and a fixed portion 73b in the apparatus, and are deformed between the fixed portions 73a and 73b so that the substrate stage 71 can freely move on the base 72. Has become.

[0005]

FIGS. 10 to 12 schematically show various states of the cables 73 when the substrate stage 71 moves on the base 72. FIGS. FIG.
11 shows a state where the substrate stage 71 is located at the center of the base 72, FIG. 11 shows a state where the substrate stage 71 is located at the upper left of the base 72, and FIG. 12 shows a state where the substrate stage 71 is located at the lower right of the base 72. Respectively.

Now, when the substrate stage 71 moves from the position shown in FIG. 10 to the position shown in FIGS. 11 and 12, one cable fixing portion 73 fixing the cables 73 is provided.
While a moves together with the substrate stage 71, the other cable fixing portion 73b is fixed. Therefore, as the substrate stage 71 moves, the cables 73 expand and contract between the two cable fixing portions 73a and 73b. At this time, a reaction force 74 indicated by an arrow in each drawing acts on the substrate stage 71 via the cable fixing portion 73a as the cables 73 try to return to the original state.
Since the direction and magnitude of the reaction force 74 are not constant depending on the state of expansion and contraction of 3, the disturbance to the substrate stage 71 for performing precise positioning is exerted and adversely affects the positioning accuracy of the substrate stage 71. The present invention has been made in view of such problems of the conventional substrate stage, and has as its object to provide an exposure apparatus in which positioning accuracy of the substrate stage and the like is not affected by cables.

[0007]

In order to achieve this object, an exposure apparatus according to the present invention is an exposure apparatus for exposing a mask on a mask pattern onto a substrate. A two-dimensionally movable substrate stage, and a substrate stage which is physically separated from the substrate base surface;
A cable relay unit that fixes cables connected to the substrate stage and is movable in the same two-dimensional direction as the substrate stage, and always keeps a relative position between the substrate stage and the cable relay unit constant. And driving means for controlling the amount of movement of the cable relay means.

[0008] According to this, the cable relay means moves following the substrate stage, and the relative positional relationship between the cable relay means and the substrate stage is always kept constant. As a result, the shape of the cable routed between the substrate stage and the cable relay means is always kept constant, so that the direction and magnitude of the reaction force exerted by the cables on the substrate stage are always kept constant. . Therefore, there is no change in the reaction force,
The movement accuracy of the stage can be secured.

Further, when the reticle stage is configured to be movable, it is preferable that the reticle stage has the same configuration. In order to prevent the stage from being affected by the driving of the cable relay means, it is preferable that the driving portion is disposed on a sub-base portion which is physically separated from the base body.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In addition, each drawing schematically shows the components of the present invention mainly with respect to the stage device, and the dimensions and shapes do not always match those of the actual device. To simplify the description, the same components are denoted by the same reference numerals as much as possible, and redundant description will be omitted.

FIG. 1 is a schematic view of an embodiment of the exposure apparatus of the present invention. The present exposure apparatus is an apparatus for projecting light from the illumination system 1 onto a mask 7 and exposing a mask pattern 8 of the mask 7 to a photosensitive surface 13 of a photosensitive substrate 12 via a projection lens 11. The illumination system 1 and the projection lens 11 are supported by a frame 2, and the frame 2 is disposed on a hard mount 57 made of rubber, for example, which absorbs vibration so as not to receive vibration from the floor. The mask 7 having the mask pattern 8 is mounted on a reticle stage 9, and the reticle stage 9 is movable in a two-dimensional direction (XY directions) along a surface of the reticle base 19 along the surface. The movement of the reticle stage 9 in the X and Y directions is performed by a magnetic levitation type planar motor formed between the reticle stage 9 and the reticle base 19.

On the other hand, the photosensitive substrate 12 arranged opposite to the mask 7 is placed on a loading table 14 via actuators 16A to 16C provided on a substrate stage 15.
Is placed on top. These actuators 16A-16
The position of the photosensitive substrate 12 in the Z direction and the angle between the photosensitive substrate 12 and the substrate stage 15 can be adjusted by adjusting the amount of movement of each of the Cs in the Z direction.
The substrate stage 15 is movable on the substrate base 17 in a two-dimensional direction along the surface. This movement is performed by a magnetic levitation type planar motor configured between them. The substrate stage 15 and the reticle stage 9 are relatively moved in synchronization with each other. The substrate base 17 and the reticle base 19 are integrated by a frame 18, and the floor portion 3 mounted on the floor via various vibration isolating members 6 using an elastic body such as a spring or an air damper or an actuator. Is placed on top.

The substrate base 17 and the reticle base 19 are
The other end of the frame 18 is connected to the frame 5 fixed to the floor by a vibration isolator 56 using a voice coil motor (VCM) or the like. Here, when using the VCM, the stator side is arranged on the frame 5 side, and the mover side is arranged on the respective bases 17 and 19 sides. Thereby, vibration (reaction force) generated by moving the substrate stage 15 and the reticle stage 5 in synchronization can be removed.

From the substrate stage 15 and the reticle stage 9, power cables and control wiring for supplying power to the respective planar motors, cooling fluid pipes for transporting the planar motor and the cooling fluid for cooling the respective stages, etc. Cables 41 and 42 which are bundled together are drawn out. These cables 41 and 42 are all connected to the robot arms 50 and 5
3 via the cable relays 51 and 54 that move two-dimensionally on the XY coordinate plane by the
5, connected to the reticle stage 9.

FIG. 2 is a perspective view of the substrate stage 15 portion. The reticle stage 9 has basically the same configuration. As described later, the robot arm 50 (53) is connected to the cable relay unit 51 regardless of the movement of the substrate stage 15 (reticle stage 9).
The cable relay unit 51 (54) follows the substrate stage 15 (reticle stage 9) so that the relative position and attitude of the substrate stage (54) relative to the substrate stage 15 (reticle stage 9) are always kept constant. To move.

As shown in FIG. 1, the robot main bodies 52, 55 of these robot arms 50, 53 are mounted on a frame 4, and this frame 4 is fixed to the floor surface independently of the floor section 3. I have. In frame 4,
Further, a substrate stage drive system 24 and a reticle stage drive system 27 to which cables 41 and 42 are connected are attached. On the other hand, an irradiation system 1 for irradiating light for exposure and for adjusting the position of the photosensitive substrate 12 and a projection optical system 11 for projecting a mask pattern 8 of a mask 7 onto a shot area 13 of the photosensitive substrate 12 include a predetermined optical system. The frame 2 is also disposed on the floor 3 via the vibration isolating member 57.

The X coordinate of the photosensitive substrate 12 is constantly monitored by a movable mirror 22X for the X axis fixed to the upper end of the table 14 and a laser interferometer 23X fixed to the frame 18, and similarly, the Y axis is The movable substrate 22Y and the external laser interferometer 23Y (see FIG. 2) are used to
Are constantly monitored, and the detected X and Y coordinates are transmitted to the stage control system 21. Stage control system 2
Reference numeral 1 denotes a substrate stage 15 and a loading table 14 via a substrate stage driving system 24 based on the transmitted coordinates.
Control the operation of. Similarly, the X coordinate of the mask 8 is constantly monitored by the X-axis movable mirror 25X fixed to the upper end of the reticle stage 9 and the laser interferometer 26X fixed on the reticle base 18, and similarly, the Y-axis Moving mirror 2
5Y and external laser interferometer 26Y (not shown)
Accordingly, the Y coordinate of the mask 8 is constantly monitored, and the detected X coordinate and Y coordinate are transmitted to the stage control system 21.
The stage control system 21 controls the operation of the reticle stage 9 via the reticle stage drive system 27 based on the transmitted coordinates. The stage control system 21 and the irradiation system 1 are controlled by the main control system 20.

Various known alignment methods can be used for adjusting the spatial position of the shot region 13 of the photosensitive substrate 12 and the mask pattern 8 of the mask 7. As the alignment method, an LSA (Laser Step Alignment) method that irradiates a laser beam onto an alignment mark in a dot row and detects the position of the alignment mark using light diffracted or scattered from the alignment mark, a diffraction grating type For example, an LIA (Laser Interferometric Alignment) that irradiates the alignment mark with laser light whose frequency is slightly changed from two directions, causes two generated diffracted lights to interfere with each other, and measures the position of the alignment mark from its phase.
t) method, FIA (Field Image Alignm) that performs image processing and measures image data of alignment marks imaged by illuminating with wide wavelength bandwidth light using a halogen lamp as a light source.
ent) method. These systems are described in U.S. Pat. Nos. 5,151,750 and 4,780,617.

These alignment methods include a TTL (through-the-lens) method for measuring the position of a photosensitive substrate via a projection optical system, and a positional relationship between a reticle and a photosensitive substrate via a projection optical system and a reticle. It is roughly classified into a TTR (through the reticle) method for measuring and an off-axis method for directly measuring the position of the photosensitive substrate without using a projection optical system. As illumination light (alignment light) for illuminating the alignment mark, there are a case where non-exposure light having a wavelength different from that of the exposure light and which is insensitive to the photosensitive layer on the photosensitive substrate is used, and a case where the exposure light itself is used. .

FIG. 1 shows an example of the TTR system.
The present invention is not limited to this, and various alignment methods such as a TTL method and an off-axis method can be adopted. These alignment adjustments are performed by the main control system 2
Controlled by 0. Hereinafter, the moving stage of the exposure apparatus of the present invention will be described by taking the substrate stage 15 as an example, but the reticle stage 9 operates on basically the same principle. Therefore, detailed description of the reticle stage 9 is omitted, but those skilled in the art can sufficiently understand the reticle stage 9 from the following description of the substrate stage 15.

FIG. 3 is a diagram showing the structure of the lower surface of the substrate stage 15. On the lower surface of the substrate stage 15, air ejecting portions 61a to 61d for ejecting air for levitation are provided at, for example, four corners thereof, and electromagnets 62a to 62d constituting movable elements of the levitation type planar motor are adjacent to each other. It is arranged in the middle area of the air ejection part. Electromagnet 6
2a to 62d each have a multi-phase winding 63,
And the winding direction of the electromagnet 62c, the winding direction of the electromagnet 62b and the winding direction of the electromagnet 62d are the same, and the winding direction of the electromagnets 62a and 62c is orthogonal to the winding direction of the electromagnets 62b and 62d. ing.

FIG. 4 is a schematic view of the upper surface of the base. On the upper surface of the base 17, a large number of permanent magnets constituting the stator of the motor are provided with square N poles 64 and N poles 6 in the X direction and the Y direction with a square region formed of the nonmagnetic member 66 interposed therebetween.
4. Square S poles 65 and S poles 65 are arranged in a lattice so that they are arranged. The periphery of the base 17 is covered with a non-magnetic member 66. A non-magnetic thin film 67 made of ceramic or glass whose surface is polished is arranged on the magnets 64 and 65 and the non-magnetic member 66 in order to flatten the surface of the base 17.

FIG. 5 is a diagram showing the relationship between the stator and the mover of the motor. The electromagnet 62 disposed on the lower surface of the substrate stage 15 on the arrangement of the N pole and the S pole on the upper surface of the base 17 is shown.
It is a figure showing the state where one 62 of a-62d is located. The electromagnet 62 includes a first phase winding 63 a and a second phase winding 6.
3b is wound, and a first phase winding 63 is shown in FIG.
a is energized and the second phase winding 63b is interrupted. When the direction of the current is reversed depending on whether the windings 63a and 63b are moving on the north pole or the south pole, the electromagnet 62 moves on the base 17 in a fixed direction. Electromagnets 62a and 62c or electromagnets 62b and 6
When a current in the same direction is passed through 2d, the substrate stage 15
Translate in the X or Y direction. On the other hand, the electromagnet 62a
When a current of the same magnitude but of the opposite direction is applied to the electromagnets 62b and 62d or the electromagnets 62b and 62d, the substrate stage 15 rotates in the XY plane.

Although the configuration of the magnetic levitation type planar motor has been described with reference to FIGS. 3 to 5, the driving means of the stage of the present invention is not limited to this.
Driving means as described in US Pat. No. 5,278,278 may be used. 6 to 8 show the substrate stage 1 on the base 17.
It is a schematic diagram which shows the state of the cables 41 when 5 moves. The cables 41 of the substrate stage 15 are fixed to the substrate stage 15 by the fixing part 3a, and are fixed by the cable relay part 51 and the fixing part 3b. The cable relay unit 51 is moved in the XY plane by the robot arm 50.
It is dimensionally movable.

The main control system 20 supplies a drive signal to the substrate stage drive system 24 via the stage control system 21 and also supplies a drive signal to the robot arm 50 so that the cable stage relay 51 Follow the movement of That is, the main control system 20 includes the substrate stage 15
Is moved by (Δx, Δy) in the XY plane, the robot arm 50 is instructed to move the cable relay section 51 disposed at the tip thereof by the same amount (Δx, Δy) as the moving amount of the substrate stage 15. Let it. This movement amount (Δx, Δ
For the information of y), the movement command for the substrate stage 15 of the main control system 20 may be used as it is, or the substrate stage 1
5 may be obtained from the outputs of the laser interferometers 23X and 23Y that monitor the position of the table 14 arranged on the table 5.

In this way, the cable relay section 51, to which the cables 42 are fixed by the fixing section 3b, is mounted on the substrate stage 15 so that the relative position with respect to the substrate stage 15 does not change.
Moves two-dimensionally in the XY coordinate system following the movement of.
When moving the cable relay unit 51, the robot arm 50 prevents the cable relay unit 51 from rotating in the XY coordinate system, that is, the relative posture between the cable relay unit 51 and the substrate stage 15 is changed. The cable relay unit 51 is rotated with respect to the arm so as not to change.

As a result, as shown in FIGS. 6 to 8, the cables 41 extending from the substrate stage 15 can be attached to the base 17 even if the substrate stage 15 is at the center of the base 17 (see FIG. 6). Whether moving from the center to the upper right (see FIG. 7) or moving to the lower left (see FIG. 8), the same shape can always be maintained between the substrate stage 15 and the cable junction 51. . Therefore, even if the reaction force from the cables 41 acts on the substrate stage 15, the reaction force is always constant irrespective of the position of the substrate stage 15, so that the positioning accuracy of the substrate stage 15 does not deteriorate. .

[0028]

According to the present invention, since the shape of the cable extending from the substrate stage and the reticle stage to the cable junction is kept constant, the reaction force acting on the substrate stage from the cables becomes constant. The positioning accuracy of the substrate stage can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic view of a preferred embodiment of an exposure apparatus of the present invention.

FIG. 2 is a perspective view of a substrate stage device of the device of FIG.

FIG. 3 is a diagram illustrating a structure of a lower surface of the substrate stage of FIG. 2;

FIG. 4 is a schematic diagram showing a structure of a base of the substrate stage device of FIG. 2;

FIG. 5 is a diagram showing a relationship between a stator and a mover of a motor used in the substrate stage device of FIG. 2;

FIG. 6 is a schematic diagram showing one state of cables when the substrate stage moves on the substrate base.

FIG. 7 is a schematic diagram illustrating a state of a cable different from that of FIG. 6;

FIG. 8 is a schematic diagram showing a state of a cable different from those in FIGS. 6 and 7;

FIG. 9 is a conceptual diagram of a substrate stage device of a conventional exposure apparatus.

FIG. 10 is a schematic diagram illustrating one state of cables when a substrate stage moves on a substrate base in the apparatus of FIG. 9;

FIG. 11 is a schematic diagram illustrating a state of a cable different from that of FIG. 10;

FIG. 12 is a schematic diagram illustrating a state of a cable different from FIGS. 10 and 11;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Illumination system, 2, 4, 5, 18 ... Frame, 7 ... Mask, 8 ... Mask pattern, 9 ... Reticle stage, 11
... Projection lens, 12 ... Photosensitive substrate, 13 ... Photosensitive surface, 14 ...
Loading table, 15: substrate stage, 16: actuator, 17: substrate base, 19: reticle base, 20
... Main control system, 21 ... Stage control system, 24 ... Substrate stage drive system, 27 ... Reticle stage drive system, 41,42
... Cables, 50, 53 ... Robot arms, 51, 5
4: Cable relay section, 52, 55: Robot body, 5
6: Anti-vibration device, 57: Hard mount

Claims (7)

[Claims] 1. An exposure apparatus for exposing a mask pattern on a mask to a photosensitive substrate, comprising: a substrate stage on which the photosensitive substrate is placed and movable two-dimensionally along an upper surface of the substrate base; A substrate stage / cables relay unit that is physically separated from the substrate stage, and is capable of fixing cables connected to the substrate stage and moving in the same two-dimensional direction as the substrate stage; and An exposure apparatus, comprising: a substrate stage driving unit that controls an amount of movement of the substrate stage / cables relay unit so that a relative position with respect to the substrate stage / cables relay unit is always kept constant. . 2. The substrate stage / cables relay unit is held by a sub-base portion physically separated from a base body having the substrate base surface together with a driving portion of the substrate stage driving unit. Claim 1
Exposure apparatus according to the above. 3. A reticle stage on which a mask is placed and which can be moved in a two-dimensional direction along an upper surface of a reticle base parallel to the substrate base, wherein the reticle base is physically separated from the reticle base surface; A reticle stage / cables relay unit that fixes cables connected to the reticle stage and is movable in the same two-dimensional direction as the reticle stage; and a relative position between the reticle stage and the reticle stage / cables relay unit. 2. The exposure apparatus according to claim 1, further comprising: a reticle stage driving unit that controls an amount of movement of the reticle stage / cables relay unit so that a proper position is always kept constant. 4. The cable relaying means is held by a base body having a substrate base surface and a reticle base surface together with a driving portion of each of the stage driving means, and a sub base physically separated from the base body. The exposure apparatus according to claim 3, wherein 5. The exposure apparatus according to claim 2, wherein the base body is disposed on a floor via a vibration isolator. 6. An exposure apparatus for exposing a mask pattern on a mask to a photosensitive substrate, wherein the photosensitive substrate is placed and moved along the upper surface of the substrate base in a state of being in physical contact with the substrate base. A substrate stage, which is physically separated from the substrate base surface, and which is capable of moving cables following the movement of the substrate stage by fixing cables connected to the substrate stage. An exposure apparatus, comprising: 7. An exposure apparatus for exposing a mask pattern on a mask to a photosensitive substrate, comprising: a stage on which the mask or the photosensitive substrate is mounted and which moves on a predetermined base in at least one-dimensional direction; And a stage / cable relay unit which is physically separated from the stage, and which can move cables following the movement of the stage by fixing cables connected to the stage. apparatus.