JP4030634B2 - Exposure equipment - Google Patents

Description

[0001]
【Technical field】
The present invention relates to an exposure apparatus applicable to lithography technology.
[0002]
[Prior art and its problems]
In the lithography technique, for example, the surface of a workpiece is masked with a mask material, and then a photoresist is coated, and the photoresist is exposed in a required pattern. Next, this photoresist is developed (resist development) to remove the photoresist in the exposed area, and then etching the mask material to remove the portion of the mask material from which the photoresist has been removed. It has been.
[0003]
This lithography technology is used for manufacturing elements having a fine pattern such as a diffraction grating, for example, but for miniaturization of patterns and diversification of basic curved surfaces (aspherical and complicated) for forming fine patterns. Accordingly, there is a problem of how accurately the exposure beam is given to the exposure region. For example, when another groove is to be processed in a specific region in a deep groove, the exposure beam is scattered on the wall surfaces (edges) at both ends of the groove, and the target region cannot be accurately exposed. A condition can arise. This tendency becomes more prominent as the basic curved surface becomes more complicated, which eventually leads to the problem that the desired fine pattern cannot be processed.
[0004]
OBJECT OF THE INVENTION
An object of the present invention is to provide an exposure apparatus capable of performing accurate exposure on a predetermined area regardless of the basic curved surface shape of a workpiece to be exposed and the shape of a drawing pattern. More specifically, for example, an object of the present invention is to obtain an exposure apparatus that can always provide an exposure beam from the normal direction regardless of the basic curved surface shape.
[0005]
SUMMARY OF THE INVENTION
According to one aspect of the exposure apparatus of the present invention, an XY table whose position can be adjusted in two orthogonal axes; a rotational position on the first axis that is on the XY table and is orthogonal to the moving plane of the XY table An adjustable rotary table; an optical system support stage movable on a cylindrical surface around a second axis orthogonal to the first axis on the rotary table; supported by the optical system support stage; An exposure beam generator for condensing the exposure beam with the intersection of the axis and the second axis as a focal position; and a work holder for rotatably supporting the workpiece to be exposed around a third axis orthogonal to the first axis. The first axis and the third axis are located in the same vertical plane, and the second axis is located in a horizontal plane.
[0006]
In the exposure apparatus of the present invention, the work holder includes a work spindle that rotatably holds the work to be exposed, and a rotary encoder that detects a rotation angle of the work spindle, and the XY table has an X direction in a horizontal plane. And a Y table movable in the Y direction orthogonal to the X direction on the X table. The X table is an X direction servo motor, and the Y table 32 is a Y direction servo motor. It is practical that each is driven by.
[0007]
In the exposure apparatus, the exposure beam generator includes a laser light source device and a light source device that emits visible light, and a laser beam provided from the laser light source device or visible light emitted from the visible light source device. It is preferable to include a beam splitter that switches to reach the focal position, and an eyepiece that guides a light beam that is irradiated from the visible light source device and reflected by the workpiece to be exposed supported at the focal position.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
1 to 7 show a first embodiment of an exposure apparatus according to the present invention. On the bed 11, a holder 20 for the workpiece W to be exposed, an XY table 30, and a laser light source device 40 are provided side by side. The work holder 20 includes a work spindle 22 that is rotatable about a horizontal rotation axis (third axis) 21, a chuck 23 that supports the workpiece W to be exposed at the tip of the work spindle 22, a work spindle motor 24, A rotation transmission unit 25 that transmits the rotation of the motor 24 to the work spindle 22 and a rotary encoder 26 that detects the rotation angle (position) of the work spindle 22 are provided.
[0009]
The XY table 30 is movable in the X direction (left and right direction in FIG. 1) within a horizontal plane, and on the X table 31 in the Y direction (direction perpendicular to the paper surface in FIG. 1) perpendicular to the X direction. The X table 31 is driven by an X-direction servo motor 31a, and the Y table 32 is driven by a Y-direction servo motor 32a, and accurate position control is performed.
[0010]
A horizontal rotary table 34 is provided on the Y table 32 so as to be rotatable about a vertical axis (first axis) orthogonal to the rotation axis (third axis) 21 of the work holder 20 (chuck 23). On the turntable 34, a cylinder centering around a vertical axis (first axis) 33 and a horizontal axis (second axis, an axis perpendicular to the paper surface of FIG. 1) 35 orthogonal to the rotation axis (third axis) 21. An optical system support table 36 that is rotatable along the surface 35c is provided.
[0011]
A pedestal 37 is erected on the optical system support table 36 at an eccentric position from the vertical axis (first axis) 33, and an exposure beam generator 41 that emits an exposure beam is supported on the pedestal 37. . The exposure beam from the exposure beam generator 41 has an intersection point between the vertical axis (first axis) 33 and the horizontal axis (second axis) 35 as a focal position F (condensed at the intersection point). As shown in FIG. 7, the exposure beam generator 41 has a condensing lens 43 and a connector 44 at both ends of a casing 42. The connector 44 receives a laser beam from the laser light source device 40 through an optical fiber. Given. The laser beam exiting the connector 44 passes through the beam splitter 46 and enters the condensing lens 43 and is condensed at the focal position F. The beam splitter 46 once switches the laser light source device 40 to a light source device that emits light that can be visually recognized by the human eye, and is emitted from the condenser lens 43 via the connector 44 to be exposed workpiece W or an adjuster. The reflected light beam is guided to the eyepiece lens 47, and this eyepiece lens 47 can confirm the light collection state.
[0012]
At the upper end of the pedestal 37, as an adjusting means for adjusting the position of the exposure beam generator 41 (condensing position of the exposure beam), an adjustment screw 41a for the position of the exposure beam generator 41 in the optical axis direction, a vertical direction (vertical axis) (First axis) 33 direction) adjustment screw 41b and left and right direction (direction perpendicular to the paper surface of FIG. 1, horizontal axis (second axis) 35 direction) adjustment screw 41c are provided. By the adjusting screw, the focus F of the exposure beam generator 41 is adjusted so as to coincide with the intersection of the vertical axis (first axis) 33 and the horizontal axis (second axis) 35 correctly.
[0013]
The rotation position of the horizontal rotary table 34 around the vertical axis (first axis) 33 is detected and controlled by a vertical axis (first axis) servo motor 34a, and the horizontal axis (second axis) of the optical system support table 36 is detected. The rotational position around 35 is detected and controlled by a horizontal axis (second axis) servomotor 36a. By adjusting the rotational positions of the horizontal rotation table 34 and the optical system support table 36 by these motors, the direction of the exposure beam applied to the workpiece W from the exposure beam generator 41 can be arbitrarily adjusted. A particularly important point is that a state in which an exposure beam is irradiated from any normal direction on any inclined surface of the workpiece W can be created.
[0014]
The vertical axis (first axis) servo motor 34a, the horizontal axis (second axis) servo motor 36a, the work spindle motor 24, the X direction servo motor 31a, and the Y direction servo motor 32a are connected to the controller 50. It is controlled via the motor driver 51 and NC controller 52 of each axis provided. The NC controller 52 is provided with an output of the rotary encoder 26 and a coordinate value display 52a for displaying the coordinate value of each axis.
[0015]
In the exposure apparatus having the above-described configuration, the workpiece W is supported on the chuck 23 of the work holder 20, the servo motor 34a for the vertical axis (first axis), the servo motor 36a for the horizontal axis (second axis), and the work spindle motor. 24. By controlling the X-direction servo motor 31a and the Y-direction servo motor 32a, the exposure beam from the exposure beam generator 41 can be arbitrarily selected from any direction while making its focal point F coincide with the surface of the workpiece W to be exposed. It is possible to irradiate an arbitrary shape for a period of time. That is, regardless of whether the surface shape of the workpiece W to be exposed is a plane, a spherical surface, a rotationally symmetric aspherical surface, or a non-rotationally symmetric aspherical surface, for example, the exposure beam can always be irradiated from its normal direction. Of course, it does not matter whether the planar shape drawn by the exposure beam is rotationally symmetric or asymmetric. Therefore, it is possible to cope with an application in which a mask is further provided in a deep groove by a lithography technique and a specific shape is exposed to a complicated shape without any problem. FIG. 6 shows a change in the relative position between the workpiece W to be exposed and the exposure beam generator 41 as the exposure beam generator 41 is moved.
[0016]
8 to 11 show a second embodiment of the exposure apparatus according to the present invention. This embodiment is different from the first embodiment in that the exposure work W is supported on the XY table 30 of the bed 11 and the exposure beam generator 15 is provided on the bed 11 with the optical axis position fixed. Different. That is, an XY table 30 having an X table 31 and a Y table 32 is provided on the bed 11 as in the first embodiment. An arc moving table 62 is supported on the Y table 32 so as to be movable and adjustable along a cylindrical surface 61c centering on a first axis parallel to the moving plane (horizontal plane) of the XY table 30. Further, a work support base 64 is supported on 62 so as to be movable and adjustable along a cylindrical surface 63c centering on a second axis orthogonal to the first axis and parallel to the moving plane of the XY table 30. Reference numerals 62a and 64a denote servo motors for driving the arcuate moving table 62 and the work support table 64, respectively.
[0017]
On this work support base 64, when the XY table 30, the arc moving base 62 and the work support base 64 are at the reference position, the workpiece W to be exposed is placed on a third axis (work rotation axis) orthogonal to the movement plane of the XY table 30. ) A work rotation support mechanism 66 that adjusts the rotation about 65 is provided.
[0018]
On the bed 11, an exposure optical system block 15 is supported above the XY table 30 so as to be movable in the vertical direction. An exposure beam generator with the optical axis directed in the vertical direction is supported on the exposure optical system block 15. 70 is supported. The exposure optical system block 15 is driven by an exposure block servomotor 15a, and this servomotor 15a constitutes a focus adjusting means. FIG. 11 shows a configuration example of the exposure beam generator 70. The light beam from the laser light source 71 is converted into a parallel light beam via a condenser lens 72 and a collimator lens 73, and is converted into a vertical light beam via a reflection mirror 74. Then, the light is condensed at the focal position F by the condenser lens 75. The laser beam reflected by the workpiece W or the adjuster travels backward through the condenser lens 75 and the reflecting mirror 74, is reflected by the beam splitter 76, is condensed by the collimator lens 77, and is received through the pinhole 78. Incident on element 79. The pinhole 78 and the light receiving element 79 constitute a focus detector, and the control means 80 drives the servo motor 15a in accordance with the amount of light incident on the light receiving element 79, so that the exposure beam is always focused on the surface of the workpiece W to be exposed. Let
[0019]
Both the first axis and the second axis preferably coincide with the focal position (condensing position) F of the condenser lens 75 at the reference position of the XY table 30.
[0020]
Also in the second embodiment, as in the first embodiment, the exposure beam from the exposure beam generator 70 can be applied in an arbitrary direction from an arbitrary direction while making its focal point F coincide with the surface of the workpiece W to be exposed. Irradiation can be always made in an arbitrary shape as long as time, particularly from the normal direction regardless of the surface shape of the workpiece W to be exposed.
[0021]
【The invention's effect】
According to the present invention, it is possible to obtain an exposure apparatus capable of performing accurate exposure on a predetermined region regardless of the basic curved surface shape of the workpiece to be exposed and the shape of the drawing pattern.
[Brief description of the drawings]
FIG. 1 is an overall front view showing a first embodiment of an exposure apparatus according to the present invention.
2 is a partial front view showing a configuration around an optical system support stage of the exposure apparatus of FIG. 1. FIG.
3 is a partial front view showing a state in which the optical system support stage of FIG. 2 is rotated about a first axis. FIG.
FIG. 4 is a partial front view showing a state of turning about the second axis.
FIG. 5 is a partial front view showing a state in which the first shaft and the second shaft are rotated.
FIG. 6 is a partial front view showing an example of an exposure state of a workpiece to be exposed by the exposure optical system.
7 is a view showing a configuration example of an exposure optical system of the exposure apparatus in FIG. 1. FIG.
FIG. 8 is an overall front view showing a second embodiment of the exposure apparatus according to the present invention.
9 is a front view of the main part of the exposure apparatus of FIG.
10 is a view taken in the direction of the arrow X in FIG. 8;
11 is a view showing a configuration example of an exposure optical system of the exposure apparatus in FIG.
[Explanation of symbols]
W Workpiece to be exposed 11 Bed 15 Exposure optical system block 20 Workholder 21 Rotating axis (third axis)
22 Work spindle 30 XY table 31 X table 32 Y table 33 Vertical axis (first axis)
34 Horizontal rotary table 35 Horizontal axis (second axis)
36 Optical system support table 37 Base 40 Laser light source device 41 Exposure beam generator 61c Cylindrical surface 62 Arc moving table 63c Cylindrical surface 64 Work support table 65 Third axis (workpiece rotation axis)
66 Work Rotation Support Mechanism 70 Exposure Beam Generator

Claims (3)

XY table whose position can be adjusted in two orthogonal axes;
A rotary table on the XY table, the rotary position of which can be adjusted around a first axis orthogonal to the moving plane of the XY table;
An optical system support stage movable along a cylindrical surface about a second axis orthogonal to the first axis on the rotary table;
An exposure beam generator which is supported by the optical system support stage and focuses the exposure beam with the intersection of the first axis and the second axis as a focal position; and a third axis which is orthogonal to the first axis. A work holder that rotatably supports the exposure work ,
An exposure apparatus, wherein the first axis and the third axis are located in the same vertical plane, and the second axis is located in a horizontal plane . 2. The exposure apparatus according to claim 1, wherein the work holder includes a work spindle that rotatably holds the workpiece to be exposed, and a rotary encoder that detects a rotation angle of the work spindle, and the XY table has an X in a horizontal plane. An X table movable in the direction and a Y table movable in the Y direction perpendicular to the X direction on the X table. The X table is driven by an X direction servo motor, and the Y table 32 is moved in a Y direction servo. An exposure apparatus driven by a motor. 3. The exposure apparatus according to claim 1, wherein the exposure beam generator irradiates a laser light source device and a light source device that emits visible light, and a laser beam supplied from the laser light source device or the visible light source device. A beam splitter that switches so that one of the received visible light reaches the focal position, and an eyepiece that is irradiated from the visible light source device and that is guided by the light beam reflected by the exposed workpiece supported at the focal position. An exposure apparatus provided.

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