Mirror component

Abstract

To provide a mirror member that can suppress deformation associated with fastening. [Solution] The mirror member MRY comprises a first plate-shaped portion 510 fastened and fixed to a part of the stage device ST, a second plate-shaped portion 520 facing the first plate-shaped portion 510, a third plate-shaped portion 530 connecting one end of the first plate-shaped portion 510 and one end of the second plate-shaped portion 520, a fourth plate-shaped portion 540 connecting the other end of the first plate-shaped portion 510 and the other end of the second plate-shaped portion and facing the third plate-shaped portion 530, a reflective portion 535 provided on the outer surface 531 of the third plate-shaped portion 530, and a reinforcing rib 550 connecting the inner surface 532 of the third plate-shaped portion 530 and the inner surface 542 of the fourth plate-shaped portion 540.

Description

Technical Field

[0001] The present invention relates to a mirror member mounted on a stage device.

Background Art

[0002] For example, in manufacturing devices such as semiconductor manufacturing devices and flat panel displays, a stage device for positioning an object to be processed while holding it is provided. A mirror member for measuring the position of a movable part is often provided on the movable part of the stage device. By reflecting the laser light emitted from a laser length measuring device with a reflecting part provided on a part of the mirror member, the position of the movable part along a specific direction can be measured.

[0003] As described in Patent Document 1 below, the mirror member is a hollow member having a rectangular cross-sectional shape. That is, the mirror member has four plate-like parts. The above-mentioned reflecting part is formed so as to cover the outer surface of one of these plate-like parts.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Of the four plate-like parts of the mirror member, one of the three plate-like parts on which the reflecting part is not formed is fastened and fixed to a part of the stage device. When the plate-like part is deformed by the fastening force, the entire mirror member including the reflecting part is also deformed accordingly. If the reflecting part is largely deformed, the direction in which the reflected laser light travels changes, which may cause a problem in the position measurement of the stage device.

[0006] This invention has been made in view of these problems, and its objective is to provide a mirror member that can suppress deformation associated with fastening. [Means for solving the problem]

[0007] To solve the above problems, the mirror member according to the present invention is a mirror member mounted on a stage device, comprising: a first plate-shaped portion fastened and fixed to a part of the stage device; a second plate-shaped portion facing the first plate-shaped portion; a third plate-shaped portion connecting one end of the first plate-shaped portion and one end of the second plate-shaped portion; a fourth plate-shaped portion connecting the other end of the first plate-shaped portion and the other end of the second plate-shaped portion and facing the third plate-shaped portion; a reflective portion provided on the outer surface of the third plate-shaped portion; and a reinforcing rib connecting the inner surface of the third plate-shaped portion and the inner surface of the fourth plate-shaped portion.

[0008] In the mirror member with the above configuration, reinforcing ribs are provided to connect the inner surface of the third plate-like portion and the inner surface of the fourth plate-like portion. By supporting the third plate-like portion, which has a reflective surface, from the inside with the reinforcing ribs, deformation of the third plate-like portion and the reflective surface can be suppressed. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a mirror member that can suppress deformation associated with fastening. [Brief explanation of the drawing]

[0010] [Figure 1] This is a diagram showing the configuration of the stage equipment. [Figure 2] This is a diagram showing the configuration of the mirror member according to the first embodiment. [Figure 3] This figure shows the configuration of the mirror member according to the second embodiment. [Figure 4] This diagram shows the configuration of the mirror member in a comparative example. [Modes for carrying out the invention]

[0011] This embodiment will now be described with reference to the attached drawings. To facilitate understanding of the explanation, the same reference numerals are used for identical components in each drawing whenever possible, and redundant explanations are omitted.

[0012] A first embodiment will now be described. The mirror members MRX and MRY in this embodiment are both components mounted on the stage device ST. Figure 1 shows the overall configuration of the stage device ST as a perspective view. For the sake of explanation, Figure 1 shows the mutually orthogonal X, Y, and Z directions. Before describing the mirror members MRX and MRY, the configuration of the stage device ST will be described first.

[0013] The stage device ST is installed inside a flat panel display manufacturing apparatus (not shown). The stage device ST holds the glass plate GL, which is the workpiece to be processed, and moves the glass plate GL in the X direction, Y direction, etc., to position it. The stage device ST may also be installed inside, for example, a semiconductor exposure apparatus, and may hold and move the workpiece, such as a silicon wafer.

[0014] The stage device ST comprises a support base 200, a guide shaft 100, and an air pad 201.

[0015] The support base 200 is the part on which the glass plate GL, which is to be processed, is placed. The support base 200 is a plate-shaped member made of a ceramic material such as alumina. The support base 200 moves in the X direction, Y direction, etc., by a mechanism that will be described later, while holding the glass plate GL on its upper surface. A holding mechanism for holding the glass plate GL is provided on the upper surface of the support base 200, but it is not shown in Figure 1. Examples of holding mechanisms include a mechanical clamp mechanism and an electrostatic chuck.

[0016] Mirror members MRX and MRY are attached to the upper surface of the support base 200 via spacers SP. Both mirror members MRX and MRY are rod-shaped members made of ceramics. When mirror member MRX is cut perpendicular to its longitudinal direction, its outer shape is rectangular. The same is true for mirror member MRY.

[0017] The mirror member MRX is mounted on the support base 200 near the X-direction end, with its longitudinal direction aligned with the Y-direction. The X-direction side of the mirror member MRX is a reflective surface (mirror surface) that reflects laser light. By reflecting laser light emitted from a laser measuring instrument (not shown) off this reflective surface, it is possible to measure the position of the support base 200 along the X-direction.

[0018] The mirror member MRY is mounted on the support base 200 near the -Y end, with its longitudinal direction aligned with the X direction. The -Y side of the mirror member MRY is a reflective surface (mirror surface) that reflects laser light. By reflecting laser light emitted from a laser measuring instrument (not shown) off this reflective surface, it is possible to measure the position of the support base 200 along the Y direction. The specific configuration of the mirror member MRY will be described later.

[0019] The guide shaft 100 is a rod-shaped member that guides the support base 200 so that it moves in the Y direction and the -Y direction. The entire guide shaft 100 is made of a ceramic material such as alumina. When the guide shaft 100 is cut perpendicular to its longitudinal direction, its outer shape is rectangular. The guide shaft 100 is fixed to the upper surface of the support base 400, which will be described later, with its longitudinal direction aligned with the Y direction. In this embodiment, two guide shafts 100 are provided, and they are arranged side by side in the X direction, spaced apart from each other.

[0020] The air pad 201 is a member fixed to the support base 200 so as to protrude further downward from the lower surface of the support base 200. In FIG. 1, only one air pad 201 facing the guide shaft 100 from the X-direction side is depicted, but an air pad (not shown) is separately provided so as to face the guide shaft 100 from the -X direction side. That is, the guide shaft 100 is sandwiched by a pair of air pads arranged in the X direction. Since two guide shafts 100 are provided in the present embodiment, a total of four air pads similar to the air pad 201 are provided.

[0021] A minute gap is formed between the air pad 201 etc. and the guide shaft 100. Although not shown, an air supply port, a groove, etc. are formed on the surface of the air pad 201 etc. facing the guide shaft 100. When pressurized air is jetted from the supply port, the space between the air pad 201 etc. and the guide shaft 100 becomes a non-contact state. Thereby, the support base 200 can move smoothly along the guide shaft 100 (that is, in the Y direction or the -Y direction) hardly receiving frictional force. Another air pad may be provided between the surface on the Z-direction side of the guide shaft 100 and the support base 200.

[0022] As described above, the guide shaft 100 and the air pad 201 etc. constitute a hydrostatic gas bearing. Since the whole including the support base 200 and the air pad 201 etc. moves integrally along the guide shaft 100, it corresponds to the "moving body" of the above hydrostatic gas bearing. Note that the guide shaft 100 corresponds to the "fixed body" of the above hydrostatic gas bearing, but as will be described later, the guide shaft 100 can move in the X direction or the -X direction together with the support base 400.

[0023] The stage device ST further includes a support base 400, a guide shaft 300, air pads 401 etc.

[0024] The support base 400 is a plate-like member formed of ceramics such as alumina, for example. Both of the two guide shafts 100 described above are fixed to the upper surface of the support base 400.

[0025] The guide shaft 300 is a rod-shaped member that guides the support base 400 so that the support base 400 moves in the X direction and the -X direction. The entire guide shaft 300 is made of a ceramic material such as alumina. When the guide shaft 300 is cut perpendicular to its longitudinal direction, its outer shape is rectangular. The guide shaft 300 is fixed to the upper surface of a mounting base (not shown) with its longitudinal direction aligned with the X direction. In this embodiment, three guide shafts 300 are provided, and they are arranged in the Y direction, spaced apart from each other.

[0026] Of the three guide shafts 300, air pads 401, 402, and 403 are provided around the guide shaft 300 positioned at the center in the Y direction.

[0027] Air pads 401 and 402 are components fixed to the support base 400 so as to protrude further downward from the lower surface of the support base 400. Air pad 401 faces the guide shaft 300 from the -Y direction, and air pad 402 faces the guide shaft 300 from the Y direction. In other words, the central guide shaft 300 is sandwiched between the pair of air pads 401 and 402, which are aligned in the Y direction. Air pad 403 is a component fixed to the lower surface of the support base 400, facing the upper surface of the guide shaft 300.

[0028] A small gap is formed between the air pad 401 and the guide shaft 300. The configuration of the air pad 401 is the same as that of the air pad 201 described earlier. When pressurized air is injected from the supply port (not shown) of the air pad 401, a non-contact state is created between the air pad 401 and the guide shaft 300. As a result, the support base 400 can move smoothly along the guide shaft 300 (i.e., in the X direction or -X direction) with almost no frictional force.

[0029] Similar to the guide shaft 300 positioned at the center in the Y direction, air pads 401, 402, and 403 may also be placed around each of the remaining two guide shafts 300. However, in this embodiment, only air pad 403 is placed around the remaining two guide shafts 300, and air pads 401 and 402 are not placed. In other words, of the three guide shafts 300, only the guide shaft 300 positioned at the center in the Y direction constrains the position of the support base 400 in the Y direction, thereby constraining the support base 400 to move only in the X direction. The other guide shafts 300 simply support the support base 400 from below via the air pads 403.

[0030] As described above, the guide shaft 300 and the air pad 401 etc. constitute a hydrostatic gas bearing. The entire structure, including the support base 400 and the air pad 401 etc., moves together along the guide shaft 300 and therefore corresponds to the "moving body" of the hydrostatic gas bearing. The guide shaft 300 corresponds to the "fixed body" of the hydrostatic gas bearing.

[0031] The stage device ST is equipped with actuators (not shown) for applying driving force to the support bases 200 and 400. Examples of actuators that can be used include linear motors and air cylinders. By moving the support base 200 relative to the guide shaft 100 using the actuators, the glass plate GL can be moved and positioned in the Y and -Y directions. Similarly, by moving the support base 400 relative to the guide shaft 300 using the actuators, the glass plate GL can be moved and positioned in the X and -X directions.

[0032] The specific configurations of mirror members MRX and MRY will be described below. Note that the configurations of mirror member MRX and mirror member MRY are identical. Therefore, the following description will primarily focus on the specific configuration of mirror member MRY, and the specific configuration of mirror member MRX will be omitted.

[0033] Figure 2 schematically shows the configuration of the mirror member MRY in Figure 1 when viewed along the X direction. The mirror member MRY has a first plate-like portion 510, a second plate-like portion 520, a third plate-like portion 530, a fourth plate-like portion 540, and a reinforcing rib 550, and the whole of these is constructed as a single integrated member. As the material for the mirror member MRY, for example, alumina, zirconia, silicon nitride, aluminum nitride, etc. can be used.

[0034] The first plate-like portion 510 is the substantially flat portion of the mirror member MRY that is closest to the -Z direction. The first plate-like portion 510 is the part that is fastened and fixed to the upper surface of the support base 200 (i.e., part of the stage device ST). The first plate-like portion 510 is fastened and fixed to the support base 200 with its outer surface 511 parallel to the upper surface of the support base 200. The outer surface 511 may be in contact with the upper surface of the support base 200, but in this embodiment, the outer surface 511 faces the upper surface of the support base 200 via the spacer SP shown in Figure 1.

[0035] A through hole 513 is formed in the first plate-like portion 510. The through hole 513 is formed to penetrate the first plate-like portion 510 perpendicularly from the outer surface 511 to the inner surface 512. The through hole 513 is a hole for inserting a fastening member 80, such as a bolt (see Figure 4(B)), from the inside of the mirror member MRY.

[0036] A circular recess 514 is formed on the inner surface 512 of the first plate-like portion 510, surrounding the through hole 513. Therefore, the head 81 of the fastening member 80 (see Figure 4(B)) does not come into contact with the inner surface 512, but rather with the bottom surface of the recess 514.

[0037] The second plate-like portion 520 is the substantially flat portion of the mirror member MRY that is closest to the Z-direction. The outer surface 521 of the second plate-like portion 520 is parallel to the outer surface 511 of the first plate-like portion 510. The second plate-like portion 520 is the portion that faces the first plate-like portion 510 in the Z-direction.

[0038] The third plate-like portion 530 is the substantially flat portion of the mirror member MRY that is closest to the -Y direction. The third plate-like portion 530 connects one end of the first plate-like portion 510 (the end on the -Y direction side) and one end of the second plate-like portion 520 (the end on the -Y direction side). The outer surface 531 of the third plate-like portion 530 is a surface perpendicular to the outer surfaces 511 and 521.

[0039] The entire outer surface 531 is covered from the outside by a reflective portion 535. The reflective portion 535 is formed by a thin metal film, such as aluminum or silver, using a plating method. The reflective portion 535 is the part that reflects laser light emitted from a laser measuring instrument (not shown), and is also referred to as a "mirror surface".

[0040] The fourth plate-like portion 540 is the substantially flat portion of the mirror member MRY that is closest to the Y direction. The fourth plate-like portion 540 connects the other end (the Y-side end) of the first plate-like portion 510 and the other end (the Y-side end) of the second plate-like portion 520. The outer surface 541 of the fourth plate-like portion 540 is perpendicular to the outer surfaces 511 and 521, and parallel to the outer surface 531. The fourth plate-like portion 540 is the portion that faces the third plate-like portion 530 in the Y direction.

[0041] The reinforcing rib 550 is a substantially flat plate-shaped portion provided to connect the inner surface 532 of the third plate-shaped portion 530 and the inner surface 542 of the fourth plate-shaped portion 540. The reinforcing rib 550 is formed to extend perpendicularly to the outer surface 531 and the outer surface 541. In other words, the reinforcing rib 550 is formed as a plate parallel to the first plate-shaped portion 510. The reinforcing rib 550 is provided at a height position that is the center in the Z direction inside the mirror member MRY.

[0042] Through holes similar to the through hole 513 may be formed in the reinforcing rib 550 at a position directly above the through hole 513, and in the second plate-like portion 520 at a position directly above the through hole 513. This makes it possible to insert the fastening member 80 into the through hole 513 through the through holes in the second plate-like portion 520 and the reinforcing rib 550, respectively.

[0043] A mirror member MRY having the above configuration can be manufactured, for example, by forming a molded body using casting or extrusion molding, and then firing the molded body.

[0044] To explain the advantages of the above-described configuration of the mirror member MRY, the configuration of the mirror member MRY in the comparative example will be described with reference to Figure 4. Figure 4(A) shows the configuration of the mirror member MRY in this comparative example from the same viewpoint as in Figure 2.

[0045] In this comparative example, the reinforcing rib 550 is not provided inside the mirror member MRY. The other configurations are the same as in the embodiment shown in Figure 2.

[0046] If reinforcing ribs 550 are not provided inside the mirror member MRY, the following problems may occur. Figure 4(B) schematically shows the state when the first plate-shaped portion 510 of the mirror member MRY according to the comparative example is fastened and fixed to the upper surface of a support base 200 (not shown) by a fastening member 80. The fastening member 80 is inserted through the through hole 513 from the inside of the mirror member MRY and fastened. The head 81 of the fastening member 80 is housed inside the recess 514 and is in contact with the bottom surface of the recess 514.

[0047] When fastening is performed by the fastening member 80, a force as shown by arrow AR1 is applied to the bottom surface of the recess 514 in the first plate-shaped portion 510 from the head 81 of the fastening member 80. Due to the local compression caused by the force of arrow AR1 in the first plate-shaped portion 510, the so-called "Poisson effect" occurs. As a result, the first plate-shaped portion 510 is pushed outward in the direction shown by arrow AR2.

[0048] At this time, the first plate-like portion 510 is deformed by the combined effects of the force indicated by arrow AR1 and its reaction force, and the Poisson effect indicated by arrow AR2. This deformation is such that the end of the first plate-like portion 510 on the -Y side moves along arrow AR3. Specifically, the end of the first plate-like portion 510 on the -Y side moves slightly toward the Z side and lifts up, and also tilts slightly toward the Y side. A similar deformation occurs at the end of the first plate-like portion 510 on the Y side.

[0049] When the first plate-like portion 510 deforms as described above, the third plate-like portion 530 connected to it undergoes a deformation in which the central part of the outer surface 531 recedes in a concave shape toward the Y direction. The same is true for the fourth plate-like portion 540. As a result, at the height position which is the center in the Z direction, the third plate-like portion 530 and the fourth plate-like portion 540 become closer to each other. In Figure 4(B), the deformations of each part as described above are depicted in an exaggerated manner.

[0050] As described above, when the first plate-shaped portion 510 is fastened and fixed by the fastening member 80, the third plate-shaped portion 530 deforms into a concave shape, and the reflective portion 535 deforms similarly as a result. When such deformation occurs, the direction in which the laser light reflected by the reflective portion 535 is directed changes, which may cause problems in measuring the position of the support base 200.

[0051] Therefore, in the mirror member MRY (Figure 2) according to this embodiment, reinforcing ribs 550 are provided inside. By providing the reinforcing ribs 550, deformation that causes the third plate-like portion 530 and the fourth plate-like portion 540 to move closer together becomes less likely. As a result, deformation of the third plate-like portion 530 and the reflective portion 535 is suppressed.

[0052] In this embodiment, a circular recess 514 is formed around the through hole 513, and the head 81 of the fastening member 80 is housed inside the recess 514. Alternatively, the recess 514 may not be formed. However, in that case, the head 81 of the fastening member 80 will not contact the bottom surface of the recess 514, but will contact the inner surface 512 of the first plate-like portion 510. Since the inner surface 512 is not a polished surface after firing, it has relatively large irregularities. Therefore, the force from the head 81 may be locally applied to the protrusions on the inner surface 512, potentially damaging the first plate-like portion 510. Accordingly, by forming the recess 514 as in this embodiment and making the bottom surface of the recess 514 a smooth surface, the damage to the first plate-like portion 510 described above can be prevented.

[0053] The reinforcing rib 550 may be formed in a plate shape parallel to the first plate-like portion 510, as in this embodiment, but is not limited to this configuration. For example, the reinforcing rib 550 may be formed as a cylindrical portion extending in the Y direction. Alternatively, multiple reinforcing ribs 550 of this shape may be arranged in a row in the X direction inside the mirror member MRY.

[0054] The height position of the reinforcing rib 550 can be changed as appropriate. For example, within the mirror member MRY, the reinforcing rib 550 may be provided at a height position that is closer to the first plate-like portion 510 than the center in the Z direction.

[0055] In the mirror member MRY according to this embodiment, the first plate-like portion 510, the second plate-like portion 520, the third plate-like portion 530, the fourth plate-like portion 540, and the reinforcing rib 550 are all integrally formed. Alternatively, the first plate-like portion 510, the second plate-like portion 520, the third plate-like portion 530, and the fourth plate-like portion 540 may be integrally formed, while the reinforcing rib 550 may be formed as a separate member. For example, the reinforcing rib 550, which is a separate member, may be joined to the inner surfaces 532 and 542.

[0056] A second embodiment will now be described. The following will primarily focus on aspects that differ from the first embodiment, while aspects common to the first embodiment will be omitted as appropriate.

[0057] Figure 3 shows the configuration of the mirror member MRY according to this embodiment, from the same viewpoint as in Figure 2. In this embodiment, the fastening member 70 for fastening and fixing the mirror member MRY is not inserted from the inside of the mirror member MRY, but is configured to be inserted from the outside (specifically, the bottom side) of the mirror member MRY.

[0058] In this embodiment, the first plate-like portion 510 does not have a recess 514 surrounding the through hole 513. In this embodiment, the through hole 513 is formed as a hole having a constant diameter from the outer surface 511 to the inner surface 512.

[0059] A roughly cylindrical metal member 60 is fitted inside the through hole 513. The central axis of the metal member 60 coincides with the central axis of the through hole 513. Since the metal member 60 is part of the first plate-like portion 510, the inner surface 61 of the metal member 60 can be considered as the inner surface of the through hole formed in the first plate-like portion 510. A female screw 62 is formed on the inner surface 61 of the metal member 60.

[0060] A through-hole 211 is formed in the support base 200 at a position directly below the metal member 60. The through-hole 211 is formed to penetrate the support base 200 in a direction perpendicular to the upper surface. The portion of the through-hole 211 near the end on the -Z direction side is enlarged in diameter compared to other parts. This enlarged portion will also be referred to as the "enlarged diameter portion 212" below.

[0061] The fastening member 70 is a bolt for fastening and fixing the mirror member MRY to the support base 200. A head 71 is provided at one end of the fastening member 70. A male screw 72 is also formed on the side surface of the fastening member 70.

[0062] The fastening member 70 is inserted into the through hole 211 from the -Z direction with its head 71 facing the -Z direction. The head 71 is housed inside the enlarged diameter portion 212. The portion of the fastening member 70 near the end opposite the head 71 is housed inside the metal member 60. In this portion, the male thread 72 of the fastening member 70 and the female thread 62 of the metal member 60 are screwed together. By fastening the fastening member 70 in this manner, the mirror member MRY is fixed to the support base 200.

[0063] Even with this configuration, the same effects as those described in the first embodiment can be achieved. Furthermore, in the configuration of this embodiment, no force is applied to the first plate-like portion 510, such as the force indicated by arrow AR1 in Figure 4(B), that is, a force that compresses a part of the first plate-like portion 510 in the thickness direction. Therefore, deformation of the reflective portion 535 and the like, as shown in Figure 4(B), can be further suppressed.

[0064] The embodiments have been described above with reference to specific examples. However, this disclosure is not limited to these specific examples. Modifications made to these specific examples by those skilled in the art are also included within the scope of this disclosure, as long as they retain the features of this disclosure. The elements, their arrangement, conditions, shapes, etc., of each of the aforementioned specific examples are not limited to those illustrated and can be modified as appropriate. The elements of each of the aforementioned specific examples can be combined in different ways as appropriate, as long as no technical inconsistencies arise. [Explanation of Symbols]

[0065] ST: Stage equipment MRY: Mirror component 510: First plate-like part 520: Second plate-like part 530: Third plate-like part 531: Exterior 532: Inner self 535:Reflector 540: Fourth plate-like part 542: Inner self 550: Reinforcement Rib

Claims

1. A mirror component mounted on a stage device, A first plate-shaped portion is fastened and fixed to a part of the stage device, A second plate-shaped portion facing the first plate-shaped portion, A third plate-shaped portion connecting one end of the first plate-shaped portion and one end of the second plate-shaped portion, A fourth plate-shaped portion connects the other end of the first plate-shaped portion and the other end of the second plate-shaped portion, and is opposite the third plate-shaped portion. A reflective portion provided on the outer surface of the third plate-shaped portion, A mirror member characterized by comprising a reinforcing rib connecting the inner surface of the third plate-like portion and the inner surface of the fourth plate-like portion.

2. The mirror member according to claim 1, characterized in that the reinforcing rib is formed in a plate shape parallel to the first plate-like portion.

3. The mirror member according to claim 1, characterized in that the first plate-like portion, the second plate-like portion, the third plate-like portion, the fourth plate-like portion, and the reinforcing rib are all integrally formed.

Images