KR20210023820A - Exposure apparatus and height adjustment method - Google Patents

Abstract

It is possible to accurately adjust the height of the light irradiation unit. The rotation driving unit is driven to rotate the pinion 161b, and the support portion 15a on which the rack 161a meshing with the pinion 161b is installed is moved in the height direction. In addition, the zero electromagnet 163 adsorbs the support 15a by passing a current through the coil of the electromagnet 163 having the permanent magnet and the electromagnet, so that the support side sliding surface 161e and the column side sliding surface 161d ) Is in close contact, and the support part 15a is fixed by the frictional force between the support-side sliding surface 161e and the column-side sliding surface 161d.

Description

Exposure apparatus and height adjustment method

The present invention relates to an exposure apparatus and a height adjustment method.

In Patent Document 1, a ball screw is engaged at one end of a holding plate, and the drawing head is moved in a vertical direction within a predetermined range by a servo motor connected to the ball screw. A drawing device is disclosed.

Japanese Patent Publication No. 1997-320943

However, in the invention described in Patent Document 1, since the ball screw is used for the movement of the drawing head, the error of taking (non-uniformity of the traveling speed of the female screw member with respect to one revolution of the lead screw) is reduced. Occurs, and there is a problem that the drawing head cannot be accurately moved.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an exposure apparatus and a height adjustment method capable of accurately adjusting the height of an optical device that irradiates light.

In order to solve the above problems, the exposure apparatus according to the present invention is, for example, a substrate holding portion on which a substrate is placed, and a substantially rod-shaped support portion formed of a magnetic material, wherein the longitudinal direction is substantially horizontal. A frame having a supporting portion installed so as to be installed, and a rod-shaped column installed at each end of the supporting portion in a substantially vertical direction, wherein a sliding surface on the side of the supporting portion is formed on the supporting portion, and a column is formed on the supporting portion. A frame formed at a position in which a column side sliding surface faces the sliding surface on the support side, and a moving mechanism for moving the support part in a vertical direction, wherein the rack installed on the support part and the column are rotatable. A moving mechanism installed on the rack and having a pinion engaged with each other, a rotation driving part for rotating the pinion, an optical device installed on the support and irradiating light to the substrate, and installed on the pillar , A permanent electromagnet having a permanent magnet and an electromagnet, and a control unit for driving the rotation driving unit to move the support unit, and for adsorbing the support unit to the permanent magnet by flowing a current through the coil of the electromagnet, The zero electromagnet adsorbs the support and makes the support-side sliding surface and the pillar-side sliding surface in close contact, and fixes the support to the pillar by a frictional force between the support-side sliding surface and the column-side sliding surface. It is characterized by that.

According to the exposure apparatus according to the present invention, the pinion is rotated by driving the rotation driving unit, and the support portion provided with a rack engaged with the pinion is moved in the height direction. In addition, by passing a current through the coil of the electromagnet of the permanent magnet and the permanent magnet and the electromagnet, the zero electromagnet adsorbs the support, so that the sliding surface on the support side and the sliding surface on the column are brought into close contact with each other, and the sliding surface on the support side and the sliding surface on the column side are in close contact with each other. The support part is fixed by the frictional force between them. This makes it possible to accurately adjust the height of the optical device. In addition, since zero electromagnets are used for adsorption of the support, the energization time is short, and deformation, expansion, etc. of the support part by heat do not occur, so that the height adjustment of the optical device can be accurately performed.

Here, as a measurement unit installed on the support, a measurement unit having a scale installed approximately along a vertical direction and a head that reads out the value of the scale and outputs positional information is provided, and when the support unit is moved , The zero electromagnet adsorbs the support part with a second adsorption force weaker than a first adsorption force, which is an adsorption force when the moving mechanism does not move the support part, and the measurement unit continuously measures the height of the support part, and the The support-side sliding surface may slide along the column-side sliding surface. Thereby, when the support part side sliding surface and the column side sliding surface are brought into close contact with each other, the support part is not inclined, so that measurement errors in the measurement part caused by inclination of the support part can be eliminated.

Here, the second adsorption force may be approximately 20% to approximately 30% of the first adsorption force. Thereby, the difference between the measurement result by the measurement unit when the support portion is adsorbed by the second adsorption force and the measurement result by the measurement unit when the support unit is adsorbed by the first adsorption force is the smallest.

Here, a substantially thin plate-shaped guide member provided between the support part and the optical device, and a driving part provided on the frame to move the optical device in a vertical direction, and the support part comprises: Having a plate-shaped portion disposed horizontally, the plate-shaped portion is formed with a ring hole that penetrates substantially in a vertical direction, and the guide member has a substantially disk shape in plan view, and is installed on the plate-shaped portion to cover the ring hole, and the guide member In, an attachment hole is formed approximately in the center, the attachment hole is disposed in a substantially concentric shape with the annular hole, and the optical device is inserted into the attachment hole so that the optical axis substantially coincides with the center of the attachment hole, and the guide It may be fixed to the member. Thereby, the deviation of the optical axis when the drive unit moves the optical device in the height direction can be reduced to several nm or less.

Here, a moving unit for moving the substrate holding unit in a scanning direction, and a measuring unit installed on the support unit and measuring a distance to the substrate, the control unit, wherein the substrate holding unit is provided in the scanning direction. While moving, the distance to the substrate may be measured through the measuring unit, a median value may be obtained from the maximum and minimum distances to the substrate, and the driving amount of the driving unit may be calculated based on the median value. Accordingly, even if the height of the substrate changes, the optical device can always be focused on the substrate.

Here, the optical device has an AF processing unit having an AF light source that irradiates downward light and an AF (Auto Focus) sensor to which reflected light is incident, and the control unit moves the support unit while operating the AF processing unit. If the optical device is positioned at a position determined to be in focus, the sliding surface on the support side and the sliding surface on the pillar side may be brought into close contact with each other. Accordingly, even if the height of the substrate changes, the optical device can always be focused on the substrate.

In order to solve the above problems, the height adjustment method according to the present invention includes, for example, a substrate holding portion on which a substrate is placed, and a substantially rod-shaped support portion formed of a magnetic material, and a support portion provided so that the longitudinal direction is approximately horizontal. And, a frame having rod-shaped pillars installed at both ends of the support so that the longitudinal direction is substantially vertical, the support portion has a support portion side sliding surface, and the pillar has a column side sliding surface with the support portion side sliding surface A frame formed at a position facing each other, and a moving mechanism for moving the support part in a vertical direction, a rack installed in the support part substantially along a vertical direction, a pinion rotatably installed on the column and engaged with the rack, A moving mechanism having a rotation driving part for rotating the pinion, a measuring part provided in the support part, an optical device provided in the support part for irradiating light to the substrate, and a zero electric field provided in the column and having a permanent magnet and an electromagnet A height adjustment method for adjusting the height of the support by using a device having a magnet, wherein the support part is adsorbed to the zero electromagnet by applying a current to the coil of the electromagnet, and the sliding surface on the support part side and the column side A step of bringing into contact with a sliding surface; a step of driving the rotation driving part to rotate the pinion while measuring the height of the support part by the measurement part, and moving the support part in a height direction; and a current flowing through the coil to the And adsorbing the support part to a zero electromagnet with a first adsorption force stronger than the second adsorption force, and fixing the support part to the post by making the support part side sliding surface and the column side sliding surface in close contact with each other. Thereby, since the support part does not tilt when the support part is adsorbed by the second adsorption force and when the support part is adsorbed by the first adsorption force, it is possible to eliminate the measurement error of the measurement part caused by inclination of the support part.

According to the present invention, it is possible to accurately adjust the height of the light irradiation portion.

1 is a perspective view schematically illustrating an exposure apparatus 1 according to a first embodiment.
2 is a schematic diagram showing a state in which the measuring unit 40 and the laser interferometer 50 measure the position of the mask holding unit 20.
3 is a perspective view schematically showing the support portion 15a of the frame 15, as viewed from the rear side (+x side).
4 is a perspective view schematically showing the support portion 15a of the frame 15, as viewed from the front side (-x side).
Fig. 5 is a diagram schematically showing the frame 15 when cut by the plane C of Fig. 3.
6 is a perspective view of a main part schematically showing the light irradiation part 30a.
7 is a side view schematically showing the driving unit 39a.
8(A) is a diagram schematically showing the guide member 70, and FIG. 8(B) is a diagram schematically showing the guide member 70A.
9(A) is a diagram showing the positional relationship between the bottom plate 151 and the guide member 70 when the guide member 70 is attached to the bottom plate 151, and FIG. 9(B) is a support plate 153 It is a diagram showing the positional relationship between the support plate 153 and the guide member 70A when the guide member 70A is attached to ).
10 is an exploded perspective view of an attachment structure for attaching the light irradiation portion 30a to the support plate 153.
11 is a diagram showing a state in which the light irradiation part 30a is attached to the frame 15.
Fig. 12(A) is a diagram showing a state in which the light irradiation unit 30a is not moving (center of the stroke), and Fig. 12(B) is a state in which the light irradiation unit 30a is moved downward (lower stroke) Fig. 12(C) is a diagram showing a state in which the light irradiation unit 30a has moved upward (at the top of the stroke).
13 is a block diagram showing the electrical configuration of the exposure apparatus 1.
14 is a flow chart showing the flow of the height adjustment process of the exposure apparatus 1.
15 is an example of the measurement result in step S20.
Fig. 16 is a diagram schematically showing a state when the support part 15a is moved up and down, and Fig. 16(A) is a case where the support part 15a is adsorbed (this embodiment), and Fig. 16(B) and Fig. 16(C) shows a case where the support part 15a is not adsorbed.

Hereinafter, an embodiment in which the present invention is applied to an exposure apparatus that generates a photo mask by irradiating light such as a laser while moving a photosensitive substrate (eg, a glass substrate) holding in an approximately horizontal direction in a scanning direction is described. It will be described in detail with reference to the drawings by way of example. In each drawing, the same elements are denoted by the same reference numerals, and descriptions of overlapping portions are omitted.

As the photosensitive substrate, for example, a quartz glass having a very small coefficient of thermal expansion (for example, about 5.5x10 ^-7 /K) is used. The photomask produced by the exposure apparatus is, for example, an exposure mask used to manufacture a substrate for a liquid crystal display device. A photomask is one or a plurality of image device transfer patterns formed on a large, substantially rectangular substrate with one side exceeding, for example, 1 m (for example, 1400 mm x 1220 mm). Hereinafter, the term mask M is used as a concept encompassing the photosensitive substrate before, during and after processing.

However, the exposure apparatus of the present invention is not limited to the mask manufacturing apparatus. The exposure apparatus of the present invention is a concept including various apparatuses for irradiating light (including laser, ultra-violet (UV), polarized light, etc.) while moving a substrate held in a substantially horizontal direction in a scanning direction. In addition, the optical device of the present invention is not limited to a light irradiation unit that irradiates light onto a photosensitive substrate.

1 is a perspective view schematically illustrating an exposure apparatus 1 according to a first embodiment. The exposure apparatus 1 mainly includes a surface plate 11, a plate-shaped portion 12, rails 13, 14, a frame 15, a mask holding portion 20, a light irradiation portion 30, and It has a measurement unit 40 (see Fig. 2), a laser interferometer 50 (see Fig. 2), and a measurement unit 61 (61a, 61d, 61g). In addition, in FIG. 1, illustration is abbreviate|omitted about a part of the structure. In addition, the exposure apparatus 1 is maintained at a constant temperature by a temperature adjusting unit (not shown) covering the entire apparatus.

The platen 11 is a member of a substantially rectangular parallelepiped shape (thick plate shape), for example, made of stone (for example, granite) or a casting with a low expansion coefficient (for example, a nickel-based alloy). Is formed. The base 11 has an upper surface 11a that is substantially horizontal (approximately parallel to the xy plane) on the upper side (+z side).

The surface plate 11 is placed on a plurality of vibration isolation tables (not shown) placed on an installation surface (for example, a floor). Thereby, the base 11 is placed on the installation surface through the vibration isolation table. Since the vibration isolation table is already known, a detailed description is omitted. Also, a vibration isolation table is not required. On the +x side of the base 11, a loader (not shown) for attaching the mask M to the mask holding portion 20 is provided.

The rail 13 is an elongated plate-like member made of ceramic, and is fixed to the upper surface 11a of the base 11 so that the longitudinal direction follows the scanning direction (x direction). The three rails 13 have substantially the same height (position in the z direction), and the upper surface is formed with high precision and high flatness.

The rail 13 on the loader side (+x side) has an end disposed at the end of the upper surface 11a, and the rail 13 on the anti-loader side (-x side) is , The end is disposed inside the end of the upper surface 11a.

The plate-shaped part 12 is mounted on the rail 13. The plate-shaped portion 12 is a substantially plate-shaped member made of ceramic, and has a substantially rectangular shape as a whole. A guide portion (not shown) is provided on the lower surface of the plate 12 (the surface on the -z side) so that the longitudinal direction follows the x direction. As a result, the moving direction of the plate-shaped portion 12 is regulated so that the plate-shaped portion 12 does not move in the x-direction.

A rail 14 is provided on the upper surface 12a of the plate-shaped part 12. The rail 14 is fixed so that the longitudinal direction may be along the y direction. The rail 14 has substantially the same height, and the upper surface is formed with high precision and high flatness.

The mask holding portion 20 has a substantially rectangular plate shape in plan view, and is formed using a low-expansion ceramic having a ^{coefficient of thermal expansion of approximately 0.5 to 1×10 −7 /K.} As a result, deformation of the mask holding portion 20 can be prevented. Further, the mask holding portion 20 may be formed using an ultra-low-expandable glass ceramic having a ^{thermal expansion coefficient of approximately 5x10 -8 /K.} In this case, even if a temperature change that cannot be controlled has occurred, deformation of the mask holding portion 20 can be reliably prevented. Further, the mask holding portion 20 may be formed of a material that expands and contracts similarly to the mask M.

The mask holding part 20 is mounted on the rail 14. In other words, the mask holding portion 20 is provided on the upper surface 11a via the plate-shaped portion 12 and the rails 13 and 14.

A guide portion (not shown) is provided on the lower surface of the mask holding portion 20 so that the longitudinal direction follows the y direction. As a result, the movement direction of the mask holding portion 20 is regulated so that the mask holding portion 20, that is, the plate-shaped portion 12 does not move in the direction other than the y direction.

In this way, the mask holding portion 20 (plate top portion 12) is installed so as to be movable in the x direction along the rail 13, and the mask holding portion 20 is moved in the y direction along the rail 14 It is installed as possible.

The mask holding portion 20 has a substantially horizontal upper surface 20a. A mask M (not shown) is placed on the upper surface 20a. Further, bar mirrors 21, 22, and 23 are provided on the upper surface 20a (see Fig. 2).

The exposure apparatus 1 has drive units 81 and 82 (see Fig. 13) not shown. The drive units 81 and 82 are, for example, linear motors. The driving unit 81 moves the mask holding unit 20 (plate top part 12) along the rail 13 in the x direction, and the driving unit 82 moves the mask holding unit 20 along the rail 14 to y Move in the direction As the method of moving the drive units 81 and 82 to move the plate-shaped portion 12 or the mask holding portion 20, various known methods can be used.

A frame 15 is installed on the base 11. The frame 15 is formed of a magnetic material, for example, a casting with a low expansion coefficient (for example, a nickel-based alloy). The frame 15 has a support portion 15a and two pillars 15c that support the support portion 15a at both ends. The frame 15 holds the light irradiation part 30 above the mask holding part 20 (+z direction). The light irradiation part 30 is attached to the support part 15a. The frame 15 will be described in detail later.

The light irradiation part 30 irradiates light (laser light in this embodiment) to the mask M. The light irradiation unit 30 is installed at a predetermined interval (for example, approximately 200 mm apart) along the y direction. In this embodiment, seven light irradiation portions 30a, light irradiation portions 30b, light irradiation portions 30c, light irradiation portions 30d, light irradiation portions 30e, light irradiation portions 30f, and light irradiation portions 30g are provided. Have. The moving mechanism 161 (described later) is a vertical direction (z direction) of the entire light irradiation portion 30a to 30g in a range of about 10 mm so that the focal position of the light irradiation portions 30a to 30g fits the upper surface of the mask M. Move to. In addition, the driving units 39 (39a (see Fig. 6) to 39g, described later) are in the range of about 30 μm for fine adjustment of the focal position of the light irradiation units 30a to 30g. In the z direction. The light irradiation unit 30 will be described later in detail.

Each of the light irradiation units 30a to 30g is provided with a reading unit (not shown). The reading unit reads the pattern formed on the mask M.

The measuring unit 40 (see Fig. 2) is, for example, a linear encoder, and the laser interferometer 50 for measuring the position of the mask holding unit 20 is the laser interferometers 51 and 52 (Fig. In 1, the illustration is omitted, see FIG. 2). A laser interferometer 51 is installed on the pillar installed on the -y side of the frame 15. In addition, a laser interferometer 52 (not shown in Fig. 1) is provided on the +x side of the base 11.

2 is a schematic diagram showing a state in which the measuring unit 40 and the laser interferometer 50 measure the position of the mask holding unit 20. In addition, in FIG. 2, only a part of the rails 13 and 14 are shown. In Fig. 2, only the light irradiation portions 30a and 30g are shown, and illustration of the light irradiation portions 30b to 30f is omitted.

The measurement unit 40 has position measurement units 41 and 42. The position measuring units 41 and 42 have scales 41a and 42a and detection heads 41b and 42b, respectively.

The scale 41a is provided on the +y side end surface of the +y side rail 13 and the -y side end surface of the -y side rail 13. The detection head 41b is provided on the +y-side and -y-side end surfaces of the plate-shaped portion 12 (not shown in Fig. 2). In Fig. 2, illustration of the scale 41a and the detection head 41b on the +y side is omitted.

The scale 42a is provided on the +x side end face of the +x side rail 14 and the -x side end face of the -x side rail 13. The detection head 42b is provided on the +x side and -x side end faces of the mask holding portion 20. In Fig. 2, illustration of the scale 42a and the detection head 42b on the -x side is omitted.

The scales 41a and 42a are laser hologram scales, for example, and a memory is formed at a pitch of 0.512 µm (nanometers). The detection heads 41b and 42b irradiate light (e.g., laser light), acquire the light reflected from the scales 41a and 42a, and divide the signal generated thereby to obtain 1 nm, The resulting signal is divided into 1024 equal portions to obtain 0.5 nm. Since the position measuring units 41 and 42 are already known, detailed descriptions are omitted.

The light irradiation part 30a is provided with a mirror 55a having a reflective surface substantially parallel to the xz plane. The light irradiation part 30g is provided with mirrors 55b and 55c having reflective surfaces substantially parallel to the xz plane. The mirrors 55a, 55b, 55c are provided so that the positions in the x direction do not overlap.

The light irradiation part 30a is provided with a mirror 56a having a reflective surface substantially parallel to the yz plane. The light irradiation part 30g is provided with a mirror 56g having a reflective surface substantially parallel to the yz plane.

The laser interferometers 51 and 52 irradiate four laser beams. The laser interferometer 51 has laser interferometers 51a, 51b, and 51c. The laser interferometer 52 has laser interferometers 52a and 52g.

In Fig. 2, the path of the laser light is indicated by a dashed-dotted line. Two of the lights irradiated from the laser interferometers 51a, 51b, and 51c are reflected by the rod mirror 23, and the reflected light is received by the laser interferometers 51a, 51b, and 51c.

Of the light irradiated from the laser interferometer 51a, the remaining two are reflected by the mirror 55a, and the reflected light is received by the laser interferometer 51a. Of the light irradiated from the laser interferometer 51b, the remaining two are reflected by the mirror 55b, and the reflected light is received by the laser interferometer 51b. Of the light irradiated from the laser interferometer 51c, the remaining two are reflected by the mirror 55c, and the reflected light is received by the laser interferometer 51c.

The laser interferometers 51a to 51c measure the positions of the bar mirrors 23 based on the positions of the mirrors 55a to 55c, respectively, so that the light irradiation units 30a and 30g and the mask holding unit 20 ) And measure the positional relationship in the y-direction.

Of the light irradiated from the laser interferometer 52a, two are reflected by the rod mirror 22, and the reflected light is received by the laser interferometer 52a. Of the light irradiated from the laser interferometer 52g, two are reflected by the rod mirror 21, and the reflected light is received by the laser interferometer 52g.

Of the light irradiated from the laser interferometer 52a, the remaining two are reflected by the mirror 56a, and the reflected light is received by the laser interferometer 52a. Of the light irradiated from the laser interferometer 52g, the remaining two are reflected by the mirror 56g, and the reflected light is received by the laser interferometer 52g.

The laser interferometers 52a and 52g measure the positions of the rod mirrors 21 and 22 based on the positions of the mirrors 56a and 56g, respectively, so that the light irradiation units 30a to 30g and the mask holding unit 20 are Measure the positional relationship in the x direction.

In this embodiment, a mirror is not provided in the light irradiation parts 30b to 30f, and a laser interferometer for measuring the position of the mirror is not provided. This is because the deviation of the optical axis when moving the light irradiation portions 30a to 30g in the z direction in the range of about 30 μm is small (more than a few nm) (described later), and the position of the light irradiation portions 30b to 30f is changed to the light irradiation portion 30a. , 30g) is calculated by interpolation. Thereby, the device can be downsized and the cost can be reduced.

Next, the frame 15 will be described. 3 and 4 are perspective views schematically showing the support portion 15a of the frame 15. 3 is a view viewed from the rear side (-x side), and FIG. 4 is a view viewed from the front side (+x side). 3 and 4 show the support portion 15a and the pillar 15c somewhat separated from each other for explanation, in reality, the support portion 15a and the pillar 15c are adjacent to each other.

The support portion 15a has a substantially rectangular shape in cross-sectional shape and a substantially rod-like shape, and the inside is hollow. The support portion 15a is disposed so that the longitudinal direction is substantially horizontal (here, the y direction). The pillars 15c are provided at both ends of the support portion 15a, respectively.

The support portion 15a mainly includes a bottom plate 151, a support plate 153, side plates 152 and 154 provided on both sides of the bottom plate 151 and the support plate 153, and partition walls 159. The bottom plate 151 and the support plate 153 are disposed substantially horizontally, and the side plates 152 and 154 are disposed substantially vertically.

In this embodiment, the plate thickness of the bottom plate 151, the support plate 153, and the side plates 152, 154 is approximately 15 mm to 20 mm, and the bottom plate 151, the support plate 153, and the side plate 152, 154) in the y direction (W1 in Fig. 9) is approximately 2.2 m.

Each of the bottom plate 151 and the support plate 153 is formed with ring holes 155a to 155g and 156a to 156g along the y direction. The annular holes 155a to 155g and 156a to 156g are holes respectively penetrating the bottom plate 151 and the support plate 153 in a substantially vertical direction, and are substantially circular in plan view. In plan view, the positions of the centers of the annular holes 155a to 155g and the positions of the centers of the annular holes 156a to 156g approximately coincide.

Guide members 70 and 70A (described later) are installed in the annular holes 155a to 155g and 156a to 156g, respectively, to cover the annular holes 155a to 155g and 156a to 156g, respectively. Irradiation portions 30a to 30g are attached. In other words, the light irradiation portions 30a to 30g are provided on the frame 15 through the guide members 70 and 70A. The attachment structure for attaching the light irradiation portions 30a to 30g to the frame 15 will be described later.

In addition, ring holes 157a to 157g are formed in the bottom plate 151 adjacent to the ring holes 155a to 155g. A barrel of a reading portion (not shown) is inserted into the ring holes 157a to 157g.

Holes 152a to 152i and 154a to 154i are formed in the side plates 152 and 154, respectively. The holes 152a to 152g and 154a to 154g are installed so that the positions in the y-direction overlap with the annular holes 155a to 155g and 156a to 156g, respectively. The holes 152a to 152g and 154a to 154g are used to attach the reading portion 60 to the annular holes 157a to 157g. The holes 152h and 152i are provided on both sides of the holes 152a to 152g, respectively, and the holes 154h and 154i are provided on both sides of the annular holes 154a to 154g, respectively. The frame 15 is a casting, and the holes 152a to 152i and 154a to 154i are used as casting extraction holes to form an inner space by discharging casting sand during casting.

Although the inside of the support part 15a is hollow, a partition wall 159 is provided inside the support part 15a as reinforcement. The partition wall 159 is a plate-shaped member, and its cross section is in contact with the bottom plate 151, the support plate 153, and the side plates 152 and 154. Thereby, in the position where the partition wall 159 is installed, the cavity inside the support part 15a disappears, and vibration or deformation (bending, distortion, etc.) of the support part 15a is prevented.

The frame 15 has a moving mechanism 161 that moves the support portion 15a along the pillar 15c in the z direction. The moving mechanism 161 moves the support portion 15a in the z direction within a range of about 10 mm. The moving mechanism 161 of the present embodiment includes a rack 161a provided along the z direction in a cross section substantially perpendicular to the longitudinal direction of the support portion 15a, a pinion 161b rotatably installed on the column 15c, and , Has a rotation driving unit 161f (see Fig. 13) for rotating the pinion 161b. The rack 161a is installed at an approximately center of a cross section substantially perpendicular to the longitudinal direction of the support portion 15a, and screws or the like (not shown) are attached to the convex portion 158 protruding outward from the side surface of the support portion 15a. It is fixed by using. The pinion 161b is rotatably provided on the column 15c, and meshes with the rack 161a.

Two permanent electromagnets 163 are installed on the pillar 15c. The two zero electromagnets 163 are provided on the pillar 15c, and are disposed near both ends of the support portion 15a in the longitudinal direction. The zero electromagnet 163 is installed along the side plate 154 adjacent to the end surface where the rack 161a is installed.

The zero electromagnet 163 is a zero-electron type having a permanent magnet 163a (see Fig. 13) and an electromagnet 163b (see Fig. 13), and is built by passing a current through the coil of the electromagnet 163b only when magnetizing and demagnetizing. The permanent magnet 163a is turned on and off. Since the low-expansion alloy used for the frame 15 is a magnetic material, it can be moved by the zero electromagnet 163. Since the zero electromagnet 163 only needs to be energized for a short time (for example, about 0.2 seconds) when ON-OFF, there is little heat generation. Further, in the zero electromagnet 163, the magnetic force does not change after the permanent magnet is turned on.

Further, the zero electromagnet 163 has an adjustment dial 163c (see Fig. 13). The adjustment dial 163c adjusts the current flowing through the coil of the electromagnet 163b, and is configured to be capable of adjusting the current in 10 steps of 1 to 10, for example. In this embodiment, when the value of the adjustment dial 163c is "10", the suction force by which the zero electromagnet 163 adsorbs the support portion 15a becomes the first suction force (described later), and the adjustment dial 163c is When the value is "2" or "3" (approximately 20% to approximately 30% of the current value when the value of the adjustment dial 163c is "10"), the zero electromagnet 163 adsorbs the support part 15a. The adsorption force becomes the second adsorption force (described later). Since the current value is proportional to the magnetic flux density and the attraction force, the magnetic flux density and the attraction force of the zero electromagnet 163 are changed by adjusting the adjustment dial 163c.

The measuring part 164 is provided in the support part 15a. The measurement unit 164 includes a scale 164a (see Fig. 5) provided substantially along the vertical direction, and a detection head 164b (see Fig. 5) that reads the value of the scale 164a and outputs position information. Like the scales 41a and 42a, the scale 164a is, for example, a laser hologram scale. Like the detection heads 41b and 42b, the detection head 164b irradiates light (e.g., laser light), acquires the light reflected from the scale 164a, and based on the signal generated thereby. Get location information. The scale 164a is provided on the side plate 152 opposite to the side plate 154.

Further, the side plate 152 is provided with measurement units 61 (61a, 61d, 61g) for measuring the distance to the mask M. The measurement units 61a, 61d, and 61g are displacement sensors that detect the height of the object (here, the mask M) based on, for example, laser light emitted from the sensor. The measurement unit 61a is installed adjacent to the light irradiation unit 30a, the measurement unit 61d is installed adjacent to the light irradiation unit 30d, and the measurement unit 61g is installed adjacent to the light irradiation unit 30g. .

Fig. 5 is a diagram schematically showing the frame 15 when cut by the plane C of Fig. 3. A convex portion 161c is formed on the pillar 15c. The surface on the +x side of the convex portion 161c is a sliding surface 161d, and a scraping process, which is a polishing process to reduce frictional resistance, is performed.

The surface on the -x side of the support portion 15a is a sliding surface 161e. The sliding surface 161e is installed at a position opposite to the sliding surface 161d. The sliding surface 161e is subjected to a scraping process similar to the sliding surface 161d. Between the sliding surface 161e and the sliding surface 161d, the oil film of about several micrometers is formed by the lubricating oil collected in the minute irregularities of the sliding surfaces 161d and 161e. In this embodiment, a mineral oil having a low liquid viscosity at room temperature is used as the lubricating oil.

By rotating the pinion 161b provided on the column 15c, the support part 15a to which the rack 161a is fixed moves up and down. When the moving mechanism 161 moves the support part 15a up and down, the sliding surface 161d and the sliding surface 161e slide smoothly by the oil film formed between the sliding surface 161d and the sliding surface 161e. .

In the rack 161a, when viewed along the y direction, the teeth of the rack 161a are located on the center line c in the x direction of the support portion 15a. In other words, the teeth of the rack 161a pass through the center of the support portion 15a and are located on a line substantially parallel to the z direction. Therefore, a moment is not generated when the pinion 161b rotates to move the rack 161a (support portion 15a) up and down.

As shown in Figs. 3 and 4, a sliding surface 161d subjected to scraping is also formed on the column 15c on the side where the rack 161a and the pinion 161b are not provided. Further, a sliding surface 161e (see Fig. 5) subjected to a scraping process is formed on the support portion 15a so as to come into contact with the sliding surface.

An elastic member 160 is provided along the pillar 15c at the end of the support portion 15a. In Figs. 3 and 4, only the elastic member 160 provided at the end on the -y side is displayed, and the illustration is omitted for the elastic member 160 provided at the end at the +y side. As shown in FIG. 5, the elastic member 160 is provided below the support part 15a. A positioning member 162 is provided between the elastic member 160 and the support portion 15a. By inserting the elastic member 160 into the concave portion 162a formed on the bottom surface of the positioning member 162, the position of the elastic member 160 in the xy direction is determined, and the elastic member according to the vertical motion of the support portion 15a (160) becomes flexible. In this way, elastic members 160 installed at both ends of the support portion 15a support the weight of the support portion 15a. The support portion 15a is approximately 660 kg to 700 kg, and the elastic member 160 is capable of supporting a weight of approximately 600 kg.

The weight of the support portion 15a that the elastic member 160 cannot support is supported by the frictional force between the sliding surface 161d and the sliding surface 161e. The zero electromagnet 163 is provided on the pillar 15c, and adsorbs the support portion 15a by passing a current through the coil of the electromagnet 163b (see Fig. 13).

When the moving mechanism 161 does not move the support part 15a up and down along the column 15c, the zero electromagnet 163 adsorbs the support part 15a with the first suction force, so that the support part 15a, that is, the rack 161a ) And the sliding surface 161e move in the left direction of FIG. 5 (refer to the arrow in FIG. 5), and the sliding surface 161d and the sliding surface 161e come into close contact with each other. The first adsorption force is approximately 12000N, and the magnetic flux density of the zero electromagnet 163 when the zero electromagnet 163 adsorbs the support portion 15a with the first adsorption force is approximately 0.3T (tesla). Further, the surface pressure generated between the sliding surface 161d and the sliding surface 161e when the zero electromagnet 163 adsorbs the support portion 15a with the first suction force is approximately 0.8 MPa.

In this way, the surface pressure generated between the sliding surface 161d and the sliding surface 161e is increased, and the sliding surface 161d and the sliding surface 161e are in close contact (strongly compressed), so that the sliding surface 161d and the sliding surface are The oil film formed between (161e) and (161e) is removed. As a result, friction occurs between the sliding surface 161d and the sliding surface 161e.

Assuming that the friction coefficient between the sliding surface 161d and the sliding surface 161e when the oil film is excluded is 0.1 to 0.2, and the adsorption force of the zero electromagnet 163 is 1500 kg, the sliding surface 161d and The weight of 150 kg is supported by friction between the sliding surface 161e. Since there are two sliding surfaces on both sides of the support portion 15a, the weight ta (approximately 60 kg to 100 kg) of the support portion 15a that the elastic member 160 cannot support can be supported by frictional force. In this way, when the moving mechanism 161 does not move the support portion 15a up and down, the support portion 15a is supported so that the position of the support portion 15a in the height direction (z direction) does not change.

When the moving mechanism 161 moves the support part 15a up and down along the column 15c, the zero electromagnet 163 adsorbs the support part 15a with a weak force (second suction force). The adsorption force (second adsorption force) when the support portion 15a is moved up and down is weaker than the adsorption force (first adsorption force) when the support unit 15a is not moved up and down. In this embodiment, the second adsorption force is approximately 20% to approximately 30% of the first adsorption force. The second adsorption force is approximately 2400N to approximately 3600N, and the magnetic flux density of the zero electromagnet 163 when the zero electromagnet 163 adsorbs the support portion 15a with the first adsorption force is approximately 0.06T to approximately 0.09T. Further, the surface pressure generated between the sliding surface 161d and the sliding surface 161e when the zero electromagnet 163 adsorbs the support portion 15a with the second suction force is approximately 0.16 to approximately 0.24 MPa.

The zero electromagnet 163 adsorbs the support portion 15a with the second suction force, so that the sliding surface 161d and the sliding surface 161e come into contact with each other. At this time, the sliding surface 161d and the sliding surface 161e are not in close contact, and an oil film formed between the sliding surface 161d and the sliding surface 161e is not excluded.

Since the sliding surface 161d and the sliding surface 161e are in contact with each other, the support portion 15a does not incline with respect to the pillar 15c when the support portion 15a moves up and down. Due to the restriction of the placement position, the zero electromagnet 163 and the measurement unit 164 are disposed on the opposite side with the moving mechanism 161 interposed therebetween, but in this embodiment, the support unit 15a is not inclined, so the measurement unit 164 Even if is at a position away from the zero electromagnet 163, the measurement result of the measurement unit 164 is stable, and the support unit 15a can be moved up and down accurately.

Here, the reason why it is preferable that the second adsorption force is approximately 20% to approximately 30% of the first adsorption force is described. Tables 1 and 2 are tables showing the torque of the rotation drive unit 161f (here, the motor) when the magnetizing force of the zero electromagnet 163 is changed. Tables 1 and 2 show the results of experiments using different motors. Tables 1 and 2 are obtained by driving the rotation driving unit 161f to rotate the pinion 161b to move the support unit 15a in the height direction, and measuring the torque of the rotation driving unit 161f at that time, The value of each cell is torque (N·).

The adsorption force is proportional to the magnetic flux density of the zero electromagnet 163, that is, the voltage applied to the zero electromagnet 163. The adsorption force in Tables 1 and 2 is obtained based on the ratio of the voltage applied to the zero electromagnet 163 and the voltage applied to the zero electromagnet 163 when the magnetic flux density of the zero electromagnet 163 is maximized. In addition, 0% of adsorption power represents a demagnetization state.

Adsorption power 0% 24% 39% this
copper
Quantity -1㎜ 0.22 0.25 0.5 -2㎜ 0.26 0.31 0.54 -3㎜ 0.3 0.35 0.6 -4㎜ 0.35 0.41 0.67 -5㎜ 0.37 0.43 0.68

Adsorption power 0% 18.5% 39% this
copper
Quantity -1㎜ 0.08 0.12 0.3 -2㎜ 0.12 0.17 0.33 -3㎜ 0.15 0.2 0.38 -4㎜ 0.18 0.23 0.4 -5㎜ 0.23 0.28 0.44

As shown in Tables 1 and 2, the torque of the rotation drive unit 161f when the adsorption force is 18.5% and 24% is almost unchanged from the torque of the rotation drive unit 161f in the demagnetization state. That is, if the second adsorption force is approximately 24% or less of the first adsorption force, the oil film formed between the sliding surface 161d and the sliding surface 161e is not excluded, and the sliding surface 161d and the sliding surface 161e There is no friction between them.

On the other hand, the torque of the rotation drive unit 161f when the adsorption force is 39% is double the torque of the rotation drive unit 161f in the demagnetization state, and is significantly different from the torque of the rotation drive unit 161f in the demagnetization state. I fly. Accordingly, when the adsorption force is 39%, the oil film formed between the sliding surface 161d and the sliding surface 161e is excluded, and friction occurs between the sliding surface 161d and the sliding surface 161e. I can see that.

From the above, from the viewpoint that friction does not occur between the sliding surface 161d and the sliding surface 161e, it is not appropriate to make the second suction force approximately 39% of the first suction force, and the second suction force is It is preferable to set it to approximately 30% or less of the first adsorption force.

However, when the second adsorption force is less than approximately 20% of the first adsorption force, the measurement unit 164 is changed from a state in which the support part 15a is adsorbed by the second adsorption force to a state in which the support part 15a is adsorbed by the first adsorption force ), the measurement result changes. Accordingly, when the second adsorption force is less than approximately 20% of the first adsorption force, the sliding surface 161d and the sliding surface 161e are not in contact with each other, and when the support portion 15a moves up and down, with respect to the column 15c. It can be seen that the support portion 15a is inclined. From the above, it is preferable to set the second adsorption force to about 20% to about 30% of the first adsorption force.

Next, the light irradiation unit 30 will be described. 6 is a perspective view of a main part schematically showing the light irradiation part 30a. The light irradiation part 30a is mainly composed of a digital mirror device (DMD) 31a, an objective lens 32a, a light source part 33a, an AF processing part 34a, a normal part 35a, a flange 36a, and , Attachment portions 37a and 38a, and a driving portion 39a. The light irradiation unit 30b to the light irradiation unit 30g are respectively DMDs 31b to 31g, objective lenses 32b to 32g, light source units 33b to 33g, AF processing units 34b to 34g, and a normal unit ( 35b to 35g), flanges 36b to 36g, attachment portions 37b to 37g, 38b to 38g, and drive portions 39b to 39g. Since the light irradiation part 30b-the light irradiation part 30g have the same structure as the light irradiation part 30a, description is omitted.

The DMD 31a is a digital mirror device (DMD) and is capable of irradiating a planar laser light. The DMD 31a has a number of movable micromirrors (not shown), and light for one pixel is irradiated from one micromirror. The micromirrors are approximately 10 µm in size and are arranged in a two-dimensional shape. The DMD 31a is irradiated with light from the light source portion 33a (described later), and the light is reflected by each micromirror. The micromirror is rotatable about an axis substantially parallel to its diagonal, and can be switched between ON (reflects light toward mask M) and OFF (does not reflect light toward mask M). Since the DMD 31a is already known, a detailed description is omitted.

The objective lens 32a causes the laser light reflected by each micromirror of the DMD 31a to form an image on the surface of the mask M. At the time of drawing, light is irradiated from each of the light irradiation portions 30a to 30g, and the light forms an image on the mask M, whereby a pattern is drawn on the mask M.

The light source unit 33a mainly includes a light source 331, a lens 332, a fly eye lens 333, lenses 334 and 335, and a mirror 336. The light source 331 is, for example, a laser diode, and light emitted from the light source 331 is guided to the lens 332 through an optical fiber or the like.

Light is guided from lens 332 to fly eye lens 333. The fly-eye lens 333 is a two-dimensional arrangement of a plurality of lenses (not shown), and a plurality of point light sources are created in the fly-eye lens 333. The light passing through the fly-eye lens 333 passes through the lenses 334 and 335 (for example, a condenser lens) and becomes parallel light, and is reflected from the mirror 336 toward the DMD 31a.

The AF processing unit 34a focuses the light irradiated on the mask M on the mask M, and is mainly composed of an AF light source 341, a collimator lens 342, an AF cylindrical lens 343, and a pentagonal prism. It has (344, 345), a lens 346, and AF sensors (347, 348). The light irradiated from the AF light source 341 becomes parallel light by the collimator lens 342, becomes linear light by the AF cylindrical lens 343, and the pentagonal prism 344 It is reflected from and forms an image on the surface of the mask M. The light reflected by the mask M is reflected by the pentagonal prism 345, is condensed by the lens 346, and is incident on the AF sensors 347 and 348. The pentagonal prisms 344 and 345 bend light at a bending angle of approximately 97°. In addition, a mirror may be used instead of the pentagonal prisms 344 and 345, but since the angular shift of the mirrors causes defocusing, it is preferable to use a pentagonal prism. The AF processing unit 34a performs an auto focus process for obtaining a focusing position based on the result received from the AF sensors 347 and 348. In addition, since such an autofocus process by the optical lever is already known, detailed descriptions are omitted.

The light irradiation part 30a has a substantially cylindrical normal part 35a in which an optical system (including the objective lens 32a) is provided. A flange 36a is provided at an upper end of the normal portion 35a. The flange 36a holds the lens 332, the fly-eye lens 333, and the lenses 334 and 335 on the image side. Therefore, the center of the light irradiation part 30a is shifted in the left direction in FIG. 6 from the optical axis ax.

In addition, attachment portions 37a and 38a are provided in the normal portion 35a. The attachment portions 37a and 38a are used for attachment to the frame 15. The attachment portion 37a is provided in the vicinity of the flange 36a, and the attachment portion 38a is provided in the vicinity of the lower end of the normal portion 35a. A hollow portion 372 having a larger diameter than the outer diameter of the attachment portion 38a is formed in the attachment portion 37a. Thereby, the normal part 35a can be pulled out upward. In Fig. 6, illustration of the screw holes 371 and 381 (described later) formed in the attachment portions 37a and 38a is omitted.

The attachment part 37a (that is, the light irradiation part 30a) is moved in the vertical direction (z direction) by the drive part 39a. 7 is a side view schematically showing the driving unit 39a. The drive part 39a mainly has a piezoelectric element 391 and a connection part 392.

The piezoelectric element 391 is a solid-state actuator (Piezo-electric element) in which displacement is generated by applying a voltage. In the piezoelectric element 391, a portion that does not displace (for example, a lower end) is attached to the support portion 15a of the frame 15 via the attachment portion 395 (see Fig. 11). When a voltage is applied to the piezoelectric element 391, the piezoelectric element 391 increases, and the upper end of the piezoelectric element 391 moves upward. The dotted line in FIG. 7 indicates a state in which the piezoelectric element 391 is reduced, and the solid line in FIG. 7 indicates a state in which the piezoelectric element 391 is stretched.

The connecting portion 392 is a member having a substantially cylindrical shape whose lower end is joined to the piezoelectric element 391. The connecting portion 392 moves up and down with the expansion and contraction of the piezoelectric element 391.

At the upper end of the connecting portion 392, a convex portion 393 having an arc-shaped tip is provided. The tip end of the convex portion 393 abuts against the lower side of the attachment portion 37a (see Fig. 6). Accordingly, when the piezoelectric element 391 increases, the light irradiation portion 30a moves in the +z direction, and when the piezoelectric element 391 decreases, the light irradiation portion 30a moves in the -z direction.

A plurality of grooves 394 are formed on the side surfaces of the connecting portion 392. The groove 394 is formed so as to be cut obliquely downward as it approaches the central axis. Therefore, even if the piezoelectric element 391 is bent and stretched (see Fig. 7, double-dot chain line), the connecting portion 392 is deformed in the portion of the groove 394, and the convex portion 393 is moved in the horizontal direction. It can only be moved in the vertical direction without causing it.

Next, an attaching structure for attaching the light irradiation portions 30a to 30g to the frame 15 will be described. In the attachment structure of this embodiment, the guide member 70 is attached to the bottom plate 151, the guide member 70A is attached to the support plate 153, and the light irradiation part 30a is attached to the guide members 70 and 70A. -30g), the light irradiation portions 30a-30g are attached to the frame 15. That is, the guide members 70 and 70A are provided between the light irradiation part 30a and the frame 15 (here, the support plate 153).

First, the guide members 70 and 70A will be described. The guide members 70 and 70A are substantially thin plate-shaped members provided between the support portion 15a (the bottom plate 151 and the support plate 153) and the light irradiation portion 30.

8(A) is a diagram schematically showing the guide member 70, and FIG. 8(B) is a diagram schematically showing the guide member 70A. The guide member 70 and the guide member 70A have different diameters.

The guide members 70 and 70A are substantially thin plate-like, and have a substantially disk shape in plan view. The guide members 70 and 70A are formed of a metal having a thickness of about 0.5 to 1 mm. In this embodiment, the guide member 70 is approximately 0.5 mm, and the guide member 70A is approximately 1 mm. As the metal, stainless steel, phosphor bronze, or the like can be used, but it is preferable to use a more homogeneous phosphor bronze. In addition, about 0.5-1 mm in this invention includes an error of about 0.5 mm or less with respect to about 0.5-1 mm.

Attachment holes 74 and 74A are formed substantially in the center of the guide members 70 and 70A. Further, in the guide members 70 and 70A, a plurality of holes 77 are formed along the outer periphery, and a plurality of holes 78 are formed along the attachment holes 74 and 74A.

In the guide member 70, a plurality of substantially arc-shaped cutout holes 79A and 79B are formed, respectively, so that the guide member 70 is easily deformable. The cut-out holes 79A and 79B are arranged at equal intervals along the circumferential direction, respectively. The radius of the cut-out hole 79A is smaller than the radius of the cut-out hole 79B, and the cut-out hole 79B is disposed outside the cut-out hole 79A. In addition, the end region 79Aa including the end of the cut-out hole 79A and the end region 79Ba including the end of the cut-out hole 79B are substantially positioned in the circumferential direction. Matches. Further, the end regions 79Aa and 79Ba exist at both ends of the cutout holes 79A and 79B, respectively.

In the guide member 70A, a plurality of substantially arc-shaped cutout holes 79C and 79D are formed, respectively, so that the guide member 70A is easily deformable. The cutout holes 79C and 79D are arranged at equal intervals along the circumferential direction, respectively. The radius of the cut-out hole 79C is smaller than the radius of the cut-out hole 79D, and the cut-out hole 79D is disposed outside the cut-out hole 79C. In addition, the end region 79Ca including the end of the cut-out hole 79C and the end region 79Da including the end of the cut-out hole 79D are substantially positioned in the circumferential direction. Matches. Further, the end regions 79Ca and 79Da exist at both ends of the cutout holes 79C and 79D, respectively.

In the present embodiment, the number of cut-out holes 79A, 79B, 79C, and 79D are each four, but the position and number of cut-out holes 79A, 79B, 79C, and 79D are not limited thereto.

The position of the end region 79Aa and the end region 79Ba in the circumferential direction substantially coincides, and the overlapping positions are arranged equally (for example, approximately every 45°) in the circumferential direction. Further, the position of the end region 79Ca and the end region 79Da in the circumferential direction substantially coincide, and the overlapping positions are arranged equally (for example, approximately every 45°) in the circumferential direction. Therefore, when a radially pressing line is drawn in the radial direction from the center point of the guide members 70 and 70A, the line always passes through at least one of the cutout holes 79A to 79D. Therefore, the amount of deformation of the guide members 70 and 70A is substantially constant regardless of the location in the circumferential direction. In addition, by arranging the cutout holes 79A to 79D in this way, even if a thick thin board having a thickness of about 1 mm is used for the guide members 70 and 70A, it matches the vertical motion of the normal part 35a of approximately 30 µm. The guide members 70 and 70A expand and contract.

9(A) shows the positional relationship between the bottom plate 151 and the guide member 70 when the guide member 70 is attached to the bottom plate 151, and FIG. 9(B) shows the positional relationship between the bottom plate 151 and the support plate 153. The positional relationship between the support plate 153 and the guide member 70A when the guide member 70A is attached is shown.

Seven guide members 70 are provided on the bottom plate 151 so as to cover the ring holes 155a to 155g. Seven guide members 70A are provided on the support plate 153 so as to cover the annular holes 156a to 156g. The attachment holes 74 and 74A are disposed substantially concentrically with the circular holes 155a to 155g and 156a to 156g.

The guide member 70 and the annular holes 155a to 155g are evenly arranged in the central part of the bottom plate 151, and the guide member 70A and the annular holes 156a to 156g are in the central part of the support plate 153 Are evenly arranged. The spacing of the adjacent annular holes 155a to 155g (that is, the guide member 70) and the spacing of the adjacent annular holes 156a to 156g (that is, the guide member 70A) is the spacing of the light irradiation portions 30a to 30g Is roughly the same as

In the guide members 70 and 70A provided in the annular holes 155a and 156a, the normal part 35 of the light irradiation part 30a is provided. A light irradiation part 30b is provided in the guide members 70 and 70A provided in the annular holes 155b and 156b. Similarly, light irradiation portions 30c to 30g are provided on the guide members 70 and 70A provided in the circular holes 155c to 155g and 156c to 156g, respectively.

The annular hole 155a and the annular hole 156a are formed so that the position in planar view may overlap. Similarly, the annular holes 155b to 155g and the annular holes 156b to 156g are formed so that their positions in plan view overlap, respectively.

Next, the attachment of the light irradiation portion 30a will be described. 10 is an exploded perspective view of an attachment structure for attaching the light irradiation portion 30a to the support plate 153. In addition, the attachment structure for attaching the light irradiation portions 30b to 30g to the bottom plate 151 and the attachment structure for attaching the light irradiation portions 30b to 30g to the support plate 153 include the light irradiation portion 30a attached to the bottom plate 151 ), the description is omitted because it is the same as the attachment structure attached to ).

The guide member 70A is provided on the support plate 153 so as to cover the annular hole 156a. The guide member 70A is fixed to the support plate 153 by inserting the screw 85 into the hole 77 and screwing the screw 85 into the screw hole 156h formed in the support plate 153.

The light irradiation part 30a (that is, the normal part 35a) is attached to the guide member 70A through the attachment part 37a. The guide member 70A is fixed to the attachment portion 37a by inserting the screw 86 into the hole 78 and screwing the screw 86 into the screw hole 371. Thereby, the light irradiation part 30a is inserted into the attachment hole 74A so that the optical axis may substantially coincide with the center of the attachment hole 74A, and is fixed to the guide member 70A.

11 is a diagram schematically showing a state in which the light irradiation portion 30a is attached to the frame 15 (here, the support portion 15a). In Fig. 11, a state cut from the surface passing through the center of the attachment hole 74 and the holes 75 and 76 is shown. In Fig. 11, some configuration requirements are shown in cross section. In Fig. 11, illustration of fastening members such as screws 85 and 86 and holes in which they are installed is omitted.

The normal portion 35a is inserted into the attachment holes 74 and 74A of the guide members 70 and 70A. The guide member 70 and the attachment portion are in a state in which the attachment portion 38a is located on the upper side of the guide member 70, and the portion lower than the attachment portion 38a of the normal portion 35a is located below the guide member 70. (38a) is fixed. In addition, the guide member 70A and the guide member 70A in a state in which the attachment portion 37a is positioned above the guide member 70A, and the portion lower than the attachment portion 37a of the normal portion 35a is positioned below the guide member 70A. The attachment part 37a is fixed.

Further, when attaching the guide members 70 and 70A to the frame 15 and the light irradiation portion 30, a pressing ring may be used. By using the pressing ring, deformation of the guide members 70 and 70A can be prevented.

In plan view, since the center of the annular hole 155a and the center of the annular hole 156a substantially coincide, the light irradiation portion 30a is attached to the support portion 15a so that the optical axis ax is in a substantially vertical direction.

The hole 79A is positioned in the horizontal direction with the AF light source 341 and the AF sensors 347 and 348, respectively, so that the light irradiated downward from the AF light source 341 and the reflected light from the mask M can pass. Matches. In other words, the position of the hole 79A overlaps with the positions of the AF light source 341 and the AF sensors 347 and 348 in a plan view.

The drive part 39a is provided to the support part 15a via the attaching part 395, and pushes up the attaching part 37a, and moves it in a vertical direction. The center G of the light irradiation part 30a is located in the vicinity of the position where the drive part 39a pushes up the attachment part 37a. Therefore, the driving part 39a pushes up the light irradiation part 30a near the center G. Accordingly, the vertical motion of the light irradiation unit 30a is stabilized.

12(A) shows a state in which the light irradiation part 30a is not moving (stroke center), and FIG. 12(B) shows a state in which the light irradiation part 30a has moved downward (stroke bottom). , Fig. 12(C) shows a state in which the light irradiation unit 30a has moved upward (top of the stroke).

Since the guide members 70 and 70A are fixed to the normal part 35a through the attachment parts 37a and 38a (not shown in Fig. 12), when the normal part 35a moves up and down by the driving part 39a, it As a result, the guide members 70 and 70A deform.

The amount of movement of the normal part 35a by the drive part 39a is approximately 40 µm (approximately ±20 µm). Since the guide members 70 and 70A are made of thin metal, the guide members 70 and 70A expand and contract (elastic deformation) according to the vertical motion of the cylindrical portion 35a of approximately 40 µm. Since the guide members 70 and 70A are substantially circular in plan view, the amount of deformation of the guide members 70 and 70A is substantially constant regardless of the location, so that the normal portion 35a does not move in the xy direction.

13 is a block diagram showing the electrical configuration of the exposure apparatus 1. The exposure apparatus 1 includes a CPU (Central Processing Unit) 201, a RAM (Random Access Memory) 202, a ROM (Read Only Memory) 203, and an input/output interface (I/F) 204. Wow, it has a communication interface (I/F) 205 and a media interface (I/F) 206, these are light irradiation unit 30, position measurement unit 41, 42, laser interferometer 51, 52 , The measurement unit 61, the drive units 81 and 82, the rotation drive unit 161f, the zero electromagnet 163, the measurement unit 164, the piezoelectric element 391, and the like are connected to each other.

The CPU 201 operates based on the programs stored in the RAM 202 and ROM 203, and controls each part. Signals are input to the CPU 201 from the position measurement units 41 and 42, the laser interferometers 51 and 52, the measurement unit 61, the measurement unit 164, and the like. The signal output from the CPU 201 is output to the light irradiation unit 30, the driving units 81 and 82, the rotation driving unit 161f, the zero electromagnet 163, the piezoelectric element 391, and the like.

RAM 202 is a volatile memory. The ROM 203 is a nonvolatile memory in which various control programs and the like are stored. The CPU 201 operates based on the programs stored in the RAM 202 and ROM 203, and controls each part. Further, the ROM 203 stores a boot program executed by the CPU 201 when the exposure apparatus 1 is started, a program dependent on the hardware of the exposure apparatus 1, and drawing data on the mask M. . Further, the RAM 202 stores programs executed by the CPU 201, data used by the CPU 201, and the like.

The CPU 201 controls an input/output device 211 such as a keyboard and a mouse through the input/output interface 204. The communication interface 205 receives data from another device through the network 212 and transmits it to the CPU 201, and transmits the data generated by the CPU 201 to the other device through the network 212. .

The media interface 206 reads out programs or data stored in the storage medium 213 and stores them in the RAM 202. Further, the storage medium 213 is, for example, an IC (Integrated Circuit) card, SD (Secure Digital) card, DVD (Digital Versatile Disc), or the like.

Further, a program that realizes each function is read from the storage medium 213, for example, is installed in the exposure apparatus 1 via the RAM 202, and executed by the CPU 201.

The CPU 201 has a function of a control unit 201a that controls each part of the exposure apparatus 1 based on an input signal. The control unit 201a is constructed by executing a predetermined program read by the CPU 201. The control unit 201a drives the rotation driving unit 161f to move the support unit 15a in the z direction. Moreover, the control part 201a adsorbs the support part 15a by the 1st adsorption force or the 2nd adsorption force by passing a current through the coil of the electromagnet 163b. The processing performed by the control unit 201a will be described later.

The configuration of the exposure apparatus 1 shown in FIG. 13 is a description of the main configuration for describing the features of the present embodiment, and does not exclude, for example, a configuration included in a general information processing device. The constituent elements of the exposure apparatus 1 may be classified into more constituent elements according to the processing content, or one constituent element may perform processing of a plurality of constituent elements.

The operation of the exposure apparatus 1 configured in this way will be described. The following processing is mainly performed by the control unit 201a.

14 is a flow chart showing the flow of the height adjustment process of the exposure apparatus 1. The control unit 201a attaches the mask M to the mask holding unit 20 using a loader (not shown) (step S10). After that, the control unit 201a moves the mask holding unit 20 via the driving units 81 and 82 to adjust the position of the mask M (step S12). In addition, since the processing of steps S10 and S12 is already known, explanation is omitted.

Next, the control unit 201a moves the support portion 15a in the height direction, and moves the position of the support portion 15a in the height direction to the origin position (step S14). The origin position is obtained by the height of the mask holding part 20 (stored in advance) and the standard of the installed mask M. When these parts are at the standard value, the focus of the light irradiation part 30 is the image of the mask M. It is a location that connects to. In addition, the position in the x direction of the support part 15a in step S14 is a center position (x center).

Here, the process of moving the support part 15a in the height direction by the control part 201a is demonstrated. First, the control unit 201a passes a current through the coil of the electromagnet 163b. Since the current is adjusted by the adjustment dial 163c, the zero electromagnet 163 attracts the support portion 15a with the second attraction force. Thereafter, the control unit 201a drives the rotation driving unit 161f to rotate the pinion 161b, thereby moving the rack 161a, that is, the support unit 15a in the height direction. At this time, the control unit 201a continuously acquires the measurement result by the measurement unit 164, and drives the rotation drive unit 161f until the measurement result by the measurement unit 164 becomes a target value.

Since the zero electromagnet 163 adsorbs the support portion 15a with the second adsorption force, the sliding surface 161d and the sliding surface 161e are in contact, but between the sliding surface 161d and the sliding surface 161e. The oil film formed on is not excluded. Therefore, when the support part 15a moves in the z direction, the sliding surface 161e slides along the sliding surface 161d. In this way, when the support part 15a moves in the z direction, the support part 15a does not incline with respect to the column 15c, so that the measurement result in the measurement part 164 is stabilized.

Up to this point (steps S10 to S14) is a preparatory step for adjusting the height of the light irradiation unit 30. Next, the control unit 201a measures the height of the mask M by the measuring units 61a and 61g while moving the mask holding unit 20 in the x direction via the driving units 81 and 82 (step S20). . Then, the control unit 201a calculates an amount of movement of the light irradiation unit 30 in the height direction (a driving amount of the driving unit 39a and a movement amount of the support unit 15a) based on the measurement result in step S20 (step S22). ). Hereinafter, the process of step S22 will be described in detail.

15 is an example of the measurement result in step S20. Here, the measurement result in the measurement part 61a is illustrated, and the value obtained is a value for the light irradiation part 30a. The control unit 201a calculates the center position (thickness center) of the minimum value (BOTTOM) and the maximum value (PEAK) of the measurement result using the following equation (1).

(PEAK+BOTTOM)/2 = thickness center (One)

Further, the control unit 201a calculates the difference between the measurement result at the center position (x center) in the x direction and the thickness center as PZT-OFS. In PZT-OFS, when the position of the support part 15a in the x direction is located at the x center, and the piezoelectric element 391 is located at the center of the stroke, the focusing position of the light irradiation unit 30 is the thickness center. It is the driving amount of the piezoelectric element 391 when the height of the support part 15a is adjusted as much as possible. PZT-OFS is a positive value when the measurement result is large at the thickness center, and is negative when the measurement result is small at the thickness center.

In addition, in the present embodiment, the support part 15a is moved to the x center in step S14, and PZT-OFS is calculated based on the measurement result at the x center in step S22. For example, in step S14, the support part 15a is moved to the x center. (15a) may be moved to the -x stage, and PZT-OFS may be obtained based on the measurement result in the -x stage in step S22. That is, the x center in steps S14 and S22 is an example, and the position in the x direction is not limited to the x center.

The control unit 201a calculates a value obtained by adding a value for arranging the piezoelectric element 391 at the center of the stroke (here, 20 μm) to the PZT-OFS as the amount of movement of the light irradiation unit 30 in the vertical direction. . In addition, the value of 20 mu m varies depending on the type of the piezoelectric element 391.

In step S20, since measurement is performed using the measurement units 61a and 61g, the amount of movement in the height direction of the light irradiation units 30a and 30g is obtained from the measurement result. In step S22, the control unit 201a determines the amount of movement in the height direction of the light irradiation units 30b to 30f (thickness center and PZT) based on the amount of movement in the height direction of the light irradiation units 30a and 30g obtained directly from the measurement result. -OFS) is calculated by interpolation.

Returning to the description of FIG. 14. The control unit 201a lowers the piezoelectric element 391 by a value calculated in step S22 (a value obtained by adding 20 μm to PZT-OFS) for each of the piezoelectric elements 391 installed in the light irradiation units 30a to 30g. It drives from the position (step S24).

Next, for each of the light irradiation units 30a to 30g, the control unit 201a checks whether or not the focus of the light irradiated to the mask M through the AF processing unit 34 is aligned with the mask M, while the rotation driving unit 161f ) Is driven to move the support portion 15a in the height direction (step S26).

In step S14, since the support part 15a is adsorbed by the 2nd adsorption force, the zero electromagnet 163 continuously adsorbs the support part 15a by the 2nd adsorption force. Therefore, also in step S26, the sliding surface 161d and the sliding surface 161e abut, and the sliding surface 161e slides along the sliding surface 161d.

The AF processing unit 34 continuously obtains how far it is necessary to move to the focusing position, and the control unit 201a continuously acquires the result. The control unit 201a drives the rotation drive unit 161f while continuously acquiring the measurement result by the measurement unit 164, and moves the support unit 15a in the height direction by the movement distance determined by the AF processing unit 34.

In step S24, since the piezoelectric element 391 is driven from the lower position by a value plus 20 μm to the PZT-OFS, as a result of the movement of the support portion 15a in step S26, the piezoelectric element 391 is located in the stroke center. At this time, the light irradiated from the light irradiation unit 30 is focused on the thickness center. Accordingly, even if the height of the mask M changes, the light irradiation unit 30 can always be focused on the mask M by the movement of the piezoelectric element 391.

After that, the control unit 201a determines whether or not the light irradiated from the light irradiation unit 30 through the AF processing unit 34 is in focus on the mask M (step S28). Since the light irradiation unit 30 is moved in steps S24 and S26, the light irradiated from the light irradiation unit 30 is usually focused on the mask M in step S28. If the light irradiation unit 30 is not located at the position judged to be in focus (NO to step S28), the control unit 201a returns the process to step S26.

When the light irradiation unit 30 is positioned at a position judged to be in focus (YES in step S28), the control unit 201a passes a current through the coil of the electromagnet 163b to the zero electromagnet 163. The support part 15a is adsorbed by the first adsorption force, and the sliding surface 161d and the sliding surface 161e are brought into close contact with each other (step S30). As a result, friction occurs between the sliding surface 161d and the sliding surface 161e, and the support portion 15a is fixed to the pillar 15c by the frictional force.

Since the zero electromagnet 163 adsorbed the support portion 15a with the second adsorption force in step S14, the zero electromagnet 163 continues to adsorb the support portion 15a with the second adsorption force before step S30. When the value of the adjustment dial 163c is moved to "10" in this state, the current value flowing through the coil of the electromagnet 163b increases, and the attraction force of the zero electromagnet 163 changes from the second attraction force to the first attraction force. Due to the nature of the zero electromagnet 163, it is possible to increase the adsorption force from the second adsorption force to the first adsorption force (the adsorption force cannot be lowered from the first adsorption force to the second adsorption force).

In this embodiment, since the sliding surface 161d and the sliding surface 161e come into contact with each other when the support part 15a is moved, and the sliding surface 161d slides along the sliding surface 161e, the zero electromagnet 163 Even if the sliding surface 161d and the sliding surface 161e are brought into close contact with each other by the suction force of, the sliding surface 161d, that is, the support portion 15a, is not inclined. Therefore, even if the support part 15a is moving, even if it does not move, the measurement result in the measurement part 164 does not change.

For example, as shown in Figs. 16(B) and 16(C), the support part 15a is inclined with respect to the column 15c (the sliding surface 161d is inclined with respect to the sliding surface 161e). In the case of moving the support part 15a in the height direction (refer to the colored arrows in Figs. 16(B) and 16(C)), the support part 15a rotates when the sliding surface 161d and the sliding surface 161e are brought into close contact with each other. (Refer to the bold arrows in Figs. 16(B) and 16(C)), the measurement results in the measurement unit 164 change. Even if the inclination of the sliding surface 161d at this time is a small angle of 1° or less, or the gap between the sliding surface 161d and the sliding surface 161e is small by about several μm, the support portion 15a is large, In addition, due to the limitation that the measurement unit 164 must be provided on a surface opposite to the surface on which the zero electromagnet 163 is installed, an error that cannot be ignored occurs in the measurement result of the measurement unit 164. On the other hand, as shown in Fig. 16(A) (this embodiment), when the support portion 15a is moved in the height direction while bringing the sliding surface 161d and the sliding surface 161e into contact, the sliding surface 161d and Since the support part 15a does not incline when the sliding surface 161e is brought into close contact, the measurement result of the measurement part 164 does not change even if the support part 15a is moving or not. As described above, in the present embodiment, an error caused by inclination of the support portion 15a can be eliminated.

When the height of the support portion 15a is fixed (step S30), the control unit 201a moves the mask holding portion 20 in the x and y directions through the driving units 81 and 82, while the AF processing units 34a to 34g ), to create an AF map indicating how much light irradiated from the light irradiation units 30a to 30g needs to be moved in order to focus on the image of the mask M, and the piezoelectric element 391 It is checked whether the driving amount of) does not exceed ±20 µm (step S32). Since the creation of an AF map is already known, a description is omitted.

If the driving amount of the piezoelectric element 391 exceeds ±20 μm, the control unit 201a moves the support portion 15a in the direction in which the driving amount of the piezoelectric element 391 exceeds ±20 μm.

Thereby, the process shown in FIG. 14 is ended. In addition, the processing shown in FIG. 14 is an example, and the order of processing and processing contents are not limited to this.

After that, drawing processing not shown is performed. The control unit 201a moves the mask holding unit 20 in the x and y directions based on the measurement results of the position measuring units 41 and 42. The control unit 201a irradiates light from the light irradiation unit 30 when the mask M passes under the light irradiation unit 30 while moving the mask holding unit 20 to perform drawing processing. Since the drawing process is performed several hours after placing the mask M on the mask holding unit 20, there is sufficient margin for the control unit 201a to perform the processing of step S32.

According to the present embodiment, since the support portion 15a on which the light irradiation portion 30 is installed is moved up and down using a moving mechanism 161 including a rack 161a and a pinion 161b, Unlike in the case of using a ball screw, there is no error in handling. Therefore, it is possible to accurately adjust the height of the light irradiation portion.

In addition, according to the present embodiment, the support part 15a is adsorbed by the first adsorption force using the zero electromagnet 163, and the sliding surface 161d and the sliding surface 161e are brought into close contact with each other. By removing the oil film between the surface 161e and the sliding surface 161e, it is possible to hold the support portion 15a by the frictional force generated between the sliding surface 161d and the sliding surface 161e. In addition, the support part 15a is adsorbed with the second adsorption force (the second adsorption force <first adsorption force) using the zero electromagnet 163, and the support part 15a is brought into contact with the sliding surface 161d and the sliding surface 161e. By moving 15a up and down, the measurement result of the measurement unit 164 does not change even when the support unit 15a is moving or not, so that an error caused by the inclination of the support unit 15a can be eliminated.

In addition, according to the present embodiment, since the zero electromagnet 163 is used, the energization time is short, and deformation or expansion of the support portion 15a due to heat does not occur. Therefore, it is possible to accurately adjust the height of the support portion 15a, that is, the light irradiation portion.

As described above, embodiments of the present invention have been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like within a range not departing from the gist of the present invention are also included. Those skilled in the art can appropriately change, add, or convert each element of the embodiment.

In addition, in the present invention, "approximately" is a concept including not only the exact same case, but also an error or deformation of a degree that does not lose the identity. For example, approximately horizontal is not limited to strictly horizontal, but is a concept including, for example, an error of several degrees. In addition, for example, even when expressing only parallel, orthogonal, etc., not only the case of strictly parallel, orthogonal, etc., but also the case of substantially parallel, substantially orthogonal, etc. shall be included. In addition, in the present invention, "nearby" means to include an area of a certain range (which can be arbitrarily determined) close to a position as a reference. For example, in the case of the vicinity of A, this is a concept indicating that the region is a certain range close to A, and that even if A is included or not included.

1: Exposure device
11: Surface plate 11a: Top surface
12： Plate top 12a： Top surface
13, 14: rail
15：frame 15a：support
15c：column
20: Mask holding part 20a: Top surface
21, 22, 23: bar mirror
30(30a~30g): Light irradiation part
31(31a~31g): DMD(Digital Mirror Device)
32(32a~32g): Objective lens 33(33a~33g): Light source part
34(34a~34g): AF (Auto Focus) processing unit
35(35a~35g): Normal part 36(36a~36g): Flange
37(37a~37g), 38(38a~38g): Attachment part 39(39a~39g): Driving part
40: measurement unit 41, 42: position measurement unit
41a, 42a: scale 41b, 42b: detection head
50, 51(51a, 51b, 51c), 52(52a, 52g): laser interferometer
55a, 55b, 55c, 56a, 56g: mirror
60：Dokchobu (讀取部)
61(61a, 61d, 61g): Measuring part
70, 70A: Guide member 74, 74A: Mounting hole
75, 76, 77, 78: hole
79A, 79B, 79C, 79D: cutout holes
79Aa, 79Ba, 79Ca, 79 Da: end area
81, 82: drive unit 85, 86: screw
151： Bottom plate
152, 154: side plate 152a to 152i, 154a to 154i: hole
153： Support plate
155a~155g, 156a~156g: hole hole 156h: screw hole
157a~157g: round hole
158: convex part 159: partition wall
160: elastic member
161：Moving mechanism
161a: rack 161b: pinion
161c: Convex
161d, 161e: Sliding surface 161f: Rotation drive
162: Positioning member 162a: Recess
163：zero electromagnet 163a：permanent magnet
163b: Electromagnet 163c: Adjustment dial
164: measurement part 164a: scale
164b: detection head
201：CPU 201a：control part
202: RAM 203: ROM
204: I/O interface
205： Communication interface
206: Media interface
211: I/O device 212: Network
213: Memory medium
331: light source 332: lens
333: fly eye lens
334, 335: lens 336: mirror
341: AF light source
342: Collimator lens
343: Cylindrical lens for AF
344, 345: 5 prism 346: lens
347, 348: sensor
371： Screw hole 372： Hollow part
381: screw hole 391: piezoelectric element
392: connection part 393: convex part
394： Groove 395： Attachment

Claims (7)

A substrate holding portion on which the substrate is placed, and
A substantially rod-shaped support made of a magnetic material, a frame having a support provided so that the longitudinal direction is approximately horizontal, and a rod-shaped column provided at both ends of the support so that the longitudinal direction is approximately vertical, wherein the support part has a support part side A frame having a sliding surface formed on the pillar, and a column-side sliding surface at a position opposite to the supporting part-side sliding surface;
A moving mechanism for moving the support portion in a vertical direction, the moving mechanism having a rack provided on the support portion, a pinion rotatably installed on the column and engaged with the rack, and a rotation driving portion for rotating the pinion;
An optical device installed on the support and irradiating light to the substrate,
A zero electromagnet installed on the pillar and having a permanent magnet and an electromagnet,
And a control unit for driving the rotation driving unit to move the support unit, and for adsorbing the support unit to the permanent magnet by flowing a current through the coil of the electromagnet,
The zero electromagnet adsorbs the support and makes the support-side sliding surface and the pillar-side sliding surface in close contact, and fixes the support to the pillar by a frictional force between the support-side sliding surface and the column-side sliding surface. An exposure apparatus, characterized in that. The method of claim 1,
A measurement unit provided on the support, comprising a measurement unit having a scale installed approximately along a vertical direction, and a head that reads the value of the scale and outputs position information,
When the support part moves, the zero electromagnet adsorbs the support part with a second suction force weaker than the first suction force, which is a suction force when the moving mechanism does not move the support part, and the measurement unit continuously maintains the height of the support part. And the sliding surface on the supporting part side slides along the column-side sliding surface. The method of claim 2,
The second adsorption force is about 20% to about 30% of the first adsorption force. The method according to any one of claims 1 to 3,
A substantially thin plate-shaped guide member provided between the support part and the optical device,
It is installed on the frame and includes a driving unit for moving the optical device in a vertical direction,
The support portion has a plate-shaped portion disposed approximately horizontally,
An annular hole penetrating substantially in a vertical direction is formed in the plate-shaped portion,
The guide member has a substantially disk shape in plan view, and is installed on the plate upper portion so as to cover the annular hole,
In the guide member, an attachment hole is formed approximately in the center,
The attachment hole is disposed in a substantially concentric shape with the annular hole,
The optical device is an exposure apparatus, characterized in that the optical axis is inserted into the attachment hole so as to substantially coincide with the center of the attachment hole and fixed to the guide member. The method of claim 4,
A moving part for moving the substrate holding part in the scanning direction,
It is provided on the support and includes a measuring unit for measuring a distance to the substrate,
The control unit measures a distance to the substrate through the measurement unit while moving the substrate holding unit in the scanning direction through the moving unit, obtains a median value from the maximum and minimum distances to the substrate, and based on the median value An exposure apparatus, characterized in that the driving amount of the driving unit is obtained. The method according to any one of claims 1 to 5,
The optical device has an AF processing unit having an AF light source that irradiates downward light, and an AF sensor to which reflected light enters,
The control unit moves the support unit while operating the AF processing unit, and when the optical device is positioned at a position determined to be in focus, the sliding surface at the support unit and the sliding surface at the pillar are in close contact with each other. Device. A substrate holding portion on which the substrate is placed, and
A substantially rod-shaped support made of a magnetic material, a frame having a support provided so that the longitudinal direction is approximately horizontal, and a rod-shaped column provided at both ends of the support so that the longitudinal direction is approximately vertical, wherein the support part has a support part side A frame having a sliding surface formed on the pillar, and a column-side sliding surface at a position opposite to the supporting part-side sliding surface;
As a moving mechanism for moving the support in a vertical direction, a rack installed in the support portion substantially along a vertical direction, a pinion rotatably installed on the column and engaged with the rack, and a rotation driving portion for rotating the pinion Branches with a moving mechanism,
A measuring part installed on the support part,
An optical device installed on the support and irradiating light to the substrate,
A height adjustment method for adjusting the height of the support by using a device installed on the pillar and having a zero electromagnet having a permanent magnet and an electromagnet,
A step of flowing a current through a coil of the electromagnet to adsorb the support part to the zero electromagnet with a second suction force, so that the support part side sliding surface and the column side sliding surface come into contact with each other,
A step of driving the rotation drive unit to rotate the pinion while measuring the height of the support unit in the measurement unit, and moving the support unit in the height direction;
A step of flowing a current through the coil to adsorb the support part to the zero electromagnet with a first adsorption force stronger than the second adsorption force, to make the support part side sliding surface and the column side sliding surface in close contact with each other to fix the support part to the column. Height adjustment method comprising a.

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