Positioning apparatus, lithographic apparatus, and article manufacturing method

Abstract

To provide a technology advantageous for higher precision of positioning.SOLUTION: A positioning device has a guide, a movable body that can move in a first direction while being guided by the guide, and a driving section that drives the movable body in the first direction. The driving section includes a feed screw extending in the first direction, a nut screwed into the feed screw and moving in the first direction as the feed screw rotates, and a connecting section that connects the nut and the movable body. The connecting section includes a hollow rod having one end connected to the movable body and the other end connected to the nut, and the feed screw is inserted through the hollow portion of the rod.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a positioning apparatus, a lithographic apparatus, and an article manufacturing method. [Background technology]

[0002] A feed screw is often used to move a table in positioning devices used in machine tools, measuring instruments, robots, semiconductor manufacturing equipment, etc. In this case, the simplest configuration would be to fasten the table to a nut that threads onto the feed screw, but this would result in a decrease in feed accuracy as the effect of bending of the feed screw would be directly transmitted to the table.

[0003] Therefore, there is a method in which a spherical bearing is interposed between the nut of the feed screw and the table rather than being fixed therebetween (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 5-280609 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the use of spherical bearings in conventional technology cannot fully address misalignment between the linear guide and the feed screw. For example, the technology in Patent Document 1 can address pitching and yawing deviation angles relative to the table's direction of travel, but cannot address eccentricity in the direction perpendicular to the table's direction of travel, or in the direction perpendicular to the table's direction of travel. This can result in significant stopping position errors for stages that require precise positioning, such as those required in exposure apparatuses.

[0006] An object of the present invention is to provide a technique that is advantageous for improving the accuracy of positioning. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided a mechanism for a rotary machine having a guide, a movable body that is movable in a first direction while being guided by the guide, and a drive unit that drives the movable body in the first direction, wherein the drive unit includes a feed screw that extends in the first direction, a nut that is threadedly engaged with the feed screw and that moves in the first direction as the feed screw rotates, and a connecting unit that connects the nut and the movable body, wherein the connecting unit includes a hollow rod that is connected at one end to the movable body and at the other end to the nut, and the feed screw is inserted into the hollow portion of the rod, and the rotary machine has a mechanism for connecting the feed screw and the Inner wall of the rod and a clearance is provided between the feed screw and the feed screw to allow the feed screw to swing. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a technique that is advantageous for improving the accuracy of positioning. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing the configuration of a positioning device 100. [Figure 2] FIG. 2 is a cross-sectional view of a main part taken along line CC' in FIG. [Figure 3] 10A and 10B are diagrams showing specific examples of installation errors of a drive unit. [Figure 4] FIG. 10 is a diagram showing an example of the configuration of a spherical bearing. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0011] Fig. 1 is a perspective view showing the configuration of a positioning device 100 according to an embodiment. Fig. 2 is a cross-sectional view of a main part taken along line CC' in Fig. 1.

[0012] The positioning device 100 is configured to move a table 2, which serves as a movable body, on the upper surface 1a of a base plate 1. When the positioning device 100 is implemented as a stage device that holds and moves a substrate as described below, a substrate chuck that holds the substrate is mounted on the table 2. The upper surface 1a of the base plate 1 is a plane (a plane parallel to the XY plane) that is parallel to the Y direction (first direction) and the X direction (second direction), which are orthogonal to each other. The positioning device 100 can move the table 2 to any position in the X and Y directions on the upper surface 1a of the base plate 1, but for simplicity's sake, FIG. 1 only shows a configuration for moving the table 2 in the Y direction. The configuration for moving the table 2 in the X direction can be the same as the configuration for moving the table 2 in the Y direction, and therefore its description will be omitted.

[0013] The surface plate 1 can be fixed to, for example, the floor surface in a clean room. A pair of linear guides 3 extending in the Y direction are provided on both end surfaces of the surface plate 1 in the X direction. The linear guides 3 are guide members that guide the movement of the table 2 in the Y direction. The mover 3a is engaged with the linear guide 3 and is movable on the linear guide 3. The table 2 is mounted on the mover 3a provided on each of the pair of linear guides 3.

[0014] The positioning device 100 includes a drive unit D that drives the table 2 in the Y direction while being guided by the linear guide 3. The drive unit D may include a feed screw 4, a motor 5, a nut 6, and a connecting unit L that connects the nut 6 to the table 2. The feed screw 4 is disposed below the table 2, at the center of the X direction on the surface plate 1, so as to extend in the Y direction. The feed screw 4 may be a ball screw. The nut 6 is threadedly engaged with the feed screw 4. One end of the feed screw 4 is connected to the output shaft of the motor 5, and the feed screw 4 is rotated by the motor 5. The table 2 is connected to the nut 6 via the connecting unit L. Therefore, when the feed screw 4 is rotated, the table 2 can move in the Y direction via the nut 6.

[0015] The connecting portion L may include a rod R having one end connected to the table 2 and the other end connected to the nut 6. The rod R is a rod with a through hole (i.e., hollow), and the feed screw 4 is inserted through the hollow portion. The rod R may be a single rod, but may also be formed by joining multiple rods. In the example of FIG. 2, the rod R is made up of a first rod R1 and a second rod R2, and the first rod R1 and the second rod R2 are connected by a connecting joint 10.

[0016] In one example, one end 7a (tip of the first rod R1) and the other end 8a (tip of the second rod R2) of the rod R are formed spherically. The connecting portion L may further include a first spherical bearing 7 that swingably supports the spherical one end 7a (tip of the first rod R1) of the rod R and a second spherical bearing 8 that swingably supports the spherical other end 8a (tip of the second rod R2) of the rod R. In this case, the spherical one end 7a of the rod R (tip of the first rod R1) is connected to the table 2 via the first spherical bearing 7. In the example of FIG. 2, the first spherical bearing 7 and the table 2 are connected via a connecting member 9. Furthermore, the spherical other end 8a of the rod R (tip of the second rod R2) is connected to the flange 6a of the nut 6 via the second spherical bearing 8.

[0017] The first spherical bearing 7 and the second spherical bearing 8 each have a hollow portion similar to that of the rod R. The nut 6, rod R, first spherical bearing 7, and second spherical bearing 8 are arranged coaxially, and the feed screw 4 passes through the hollow portions that are aligned in a straight line.

[0018] With the above-described configuration, the nut 6, the rod R, the first spherical bearing 7, and the second spherical bearing 8 are integrally driven by the feed screw 4, and the table can be moved.

[0019] Furthermore, the connecting part L supports the rod R so that it can oscillate via the first spherical bearing 7 and the second spherical bearing 8. The connecting part L can absorb installation errors of the drive part D by its oscillation. To achieve this absorption of installation errors, a predetermined clearance is provided between the feed screw 4 and the inner wall of the hollow part through which the feed screw 4 passes. The directions of alignment errors that need to be addressed in this embodiment include the following directions. (1) In a horizontal plane, the direction (X direction (second direction)) perpendicular to the feed direction (Y direction (first direction)) of the table 2. (2) In a vertical plane, a direction (Z direction (third direction)) perpendicular to the feed direction (Y direction) of table 2. (3) Rotation direction (pitching) around the X-axis (axis in the second direction). (4) Direction of rotation (yawing) around the Z axis (third direction axis).

[0020] Therefore, the predetermined clearance is set so that the feed screw 4 is loosely fitted by the connecting portion L so as to be swingable in the directions indicated in (1) to (4) above.

[0021] Specific examples of installation errors of the drive unit D include a case where the linear guide 3 and the feed screw 4 become non-parallel due to pitching or yawing (deflection mode), as shown in Fig. 3(a). Alternatively, a case where the center of rotation A of the first spherical bearing 7 and / or the center of rotation B of the second spherical bearing 8 are displaced from the central axis of the feed screw 4 due to a misalignment of the first rod R1 and the second rod R2 (eccentric mode), as shown in Fig. 3(b). According to the connecting unit L of this embodiment, even in such cases, the error can be absorbed by the spherical oscillation of the first spherical bearing 7 and the second spherical bearing 8.

[0022] Next, the specific configurations of the first spherical bearing 7 and the second spherical bearing 8 will be described. Conventional spherical bearings have internal clearance, but their structure does not allow for uniform pressure to be applied in the direction perpendicular to the spherical surface, whether radial or axial pressure is applied. For this reason, conventional spherical bearings are known to be unsuitable for use on stages that require precise positioning. Figure 4 shows an example of the configuration of a spherical bearing that solves this problem. Figure 4 also shows a typical example of the specific configuration of the second spherical bearing 8. Because the first spherical bearing 7 can be configured in the same way as the second spherical bearing 8, a description of the configuration of the first spherical bearing 7 will be omitted.

[0023] 4, the second spherical bearing 8 may have a cage 13 that holds the spherical tip portion (other end 8a) of the rod R via a plurality of steel balls 14 (spherical rolling elements). The second spherical bearing 8 may also have an outer peripheral member 12 that surrounds and supports the cage 13 so as to apply pressure via the plurality of steel balls 14 to the tip portion of the rod R held by the cage 13.

[0024] The outer peripheral member 12 can be composed of a first outer peripheral member 12a and a second outer peripheral member 12b. The second spherical bearing 8 holds the spherical tip portion (other end 8a) of the rod R so that it can swing freely within a predetermined angular range using the first outer peripheral member 12a and the second outer peripheral member 12b via a cage 13. The cage 13 holds the spherical tip portion (other end 8a) of the rod R via a plurality of steel balls 14.

[0025] The first outer peripheral member 12a and the second outer peripheral member 12b can be fixed together by, for example, fastening bolts 16. The first outer peripheral member 12a and the second outer peripheral member 12b are annular in shape, centered on the hollow shaft of the rod R (the shaft of the feed screw 4), and hold the spherical tip end (other end 8a) of the rod R together with the cage 13 in a state of equal pressure via a plurality of steel balls 14 (spherical rolling elements). The inner surfaces 15 of the first outer peripheral member 12a and the second outer peripheral member 12b are spherically machined to fit and hold the cage 13. In addition, the second outer peripheral member 12b has stepped holes 17 drilled on both outer sides of the inner surface 15 to accommodate the heads and threaded portions of bolts 16 that penetrate from one surface to the other, and threaded holes 18 are threaded into the first outer peripheral member 12a.

[0026] According to the first spherical bearing 7 and the second spherical bearing 8 described above, it is possible to apply a preload and eliminate gaps. Furthermore, the spherical tip portion (other end 8a) of the rod R is fitted into the first outer peripheral member 12a and the second outer peripheral member 12b via a plurality of steel balls 14. As such, the first spherical bearing 7 and the second spherical bearing 8 are not so-called sliding bearings as in the past, but are rolling bearings using steel balls 14, so that movement is smooth even when a preload is applied.

[0027] Furthermore, an appropriate relationship is established between the angle from the joining surface between the first outer peripheral member 12a and the second outer peripheral member 12b to the lower end of the cage 13 and the angle of opening from the joining surface to the end of the inner surface 15, which is the rolling surface of the steel balls 14 of the first outer peripheral member 12a. This allows for a large allowable tilt angle, and the spherical tip end (other end 8a) of the rod R can be supported without rattle or falling off. Therefore, the first spherical bearing 7 and the second spherical bearing 8 can be said to be bearings more suitable for precision measuring instruments, precision machining machines, precision positioning mechanisms, etc.

[0028] Furthermore, the retainer 13 that holds the spherical tip portion (other end 8a) of the rod R can be configured, for example, as a divided body that is divided parallel to the receiving opening surface 19a and the opening surface 19b. Such a configuration is simple, has excellent strength, and can also simplify the assembly process.

[0029] <Application example> An application example of the positioning device according to the above-described embodiment will be described. The positioning device is useful for positioning an object in various devices, such as robots, and machines or devices related to transportation, machining, processing, measurement, and manufacturing (industrial machines or devices). For example, the positioning device is useful for positioning a stage in a stage (XY stage) device provided in a lithography device (exposure device, etc.) as industrial machinery.

[0030] A lithography apparatus is an apparatus that forms a pattern on a substrate, and can be embodied as, for example, an exposure apparatus, a writing apparatus, or an imprinting apparatus. An exposure apparatus forms a (latent image) pattern on a substrate (or on a resist thereon) using, for example, (extreme) ultraviolet light. A writing apparatus forms a (latent image) pattern on a substrate (or on a resist thereon) using, for example, a charged particle beam (such as an electron beam). An imprinting apparatus forms a pattern on the substrate by molding an imprint material on the substrate. A stage apparatus can include the above-mentioned positioning device for positioning a stage that holds and moves the substrate.

[0031] <Embodiment of an article manufacturing method> The article manufacturing method according to an embodiment of the present invention is suitable for manufacturing articles such as microdevices, such as semiconductor devices, and elements having microstructures. The article manufacturing method according to this embodiment includes a step of transferring a pattern of an original onto a substrate using the above-described lithography apparatus (such as an exposure apparatus, imprint apparatus, or drawing apparatus), and a step of processing the substrate onto which the pattern has been transferred. Furthermore, this manufacturing method includes other well-known steps (such as oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, and packaging). The article manufacturing method according to this embodiment is advantageous over conventional methods in at least one of the performance, quality, productivity, and production cost of the article.

[0032] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0033] 1: Surface plate, 2: Table, 3: Linear guide, 4: Feed screw, 5: Motor, 6: Nut, 100: Positioning device

Claims

1. With a guide, a movable body that is movable in a first direction while being guided by the guide; a drive unit that drives the movable body in the first direction, The drive unit is a feed screw extending in the first direction; a nut that is threadedly engaged with the feed screw and moves in the first direction as the feed screw rotates; a connecting portion that connects the nut and the movable body, the coupling portion includes a hollow rod having one end connected to the movable body and the other end connected to the nut, The feed screw is inserted into the hollow portion of the rod, A clearance is provided between the feed screw and the inner wall of the rod, allowing the feed screw to swing. A positioning device characterized by:

2. The one end and the other end of the rod are formed into a spherical shape, The connecting portion is a first spherical bearing that supports the spherical end of the rod so that the end can swing; a second spherical bearing that supports the spherical other end of the rod so that the other end can swing, the one end of the rod is connected to the movable body via the first spherical bearing, and the other end of the rod is connected to the nut via the second spherical bearing; 2. The positioning device according to claim 1.

3. a hollow portion is formed in each of the first spherical bearing and the second spherical bearing, the nut, the rod, the first spherical bearing, and the second spherical bearing are arranged coaxially, and the feed screw passes through hollow portions thereof; 3. The positioning device according to claim 2.

4. 4. The positioning device of claim 3, wherein a clearance between the feed screw and the inner wall of the rod is set so that the feed screw is loosely fitted to be swingable by the connecting portion in a second direction perpendicular to the first direction in a horizontal plane, a third direction perpendicular to the first direction in a vertical plane, a rotational direction around an axis of the second direction, and a rotational direction around an axis of the third direction.

5. The rods include a first rod and a second rod, The first rod and the second rod are connected by a connecting joint, A positioning device as described in claim 3 or 4, characterized in that a clearance between the feed screw and the inner wall of the rod is set so that the feed screw can be loosely fitted and swingable by the connecting portion even if a misalignment occurs in the connection between the first rod and the second rod.

6. The first spherical bearing and the second spherical bearing each include: a cage that holds the spherical tip of the rod via a plurality of spherical rolling elements; an outer peripheral member that surrounds and supports the cage so as to apply pressure to the tip portions held by the cage via the plurality of spherical rolling elements; 6. The positioning device according to claim 2, further comprising:

7. A positioning device according to any one of claims 1 to 6; a substrate chuck mounted on the movable body of the positioning device, A lithography apparatus configured to transfer a pattern of an original onto a substrate held by the substrate chuck.

8. The lithographic apparatus according to claim 7, configured as an exposure apparatus or an imprint apparatus.

9. transferring a pattern onto a substrate using a lithographic apparatus according to claim 7 or 8; processing the substrate onto which the pattern has been transferred; and manufacturing an article from the processed substrate.

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