Holding device, exposure device, and method for manufacturing articles

Abstract

To precisely hold an optical element.SOLUTION: A holding device is intended to hold an optical element that has a flat surface on an outer periphery thereof. The holding device includes: a lens barrel including a contact surface brought into contact with the flat surface; a first elastic member that presses the optical element in an optical axis direction of the optical element; and a second elastic member that presses the flat surface against the contact surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a holding device, an exposure apparatus, and a method for manufacturing an article. [Background Art]

[0002] In a lithography process for manufacturing products such as liquid crystal panels, organic EL displays, and semiconductor devices, an exposure apparatus that transfers a pattern of an original onto a substrate coated with a photosensitive agent is used. High positional accuracy is required for optical elements mounted in an exposure apparatus. However, a temperature change caused by energy of exposure light may cause thermal expansion of the optical element and a holding device that holds the optical element, resulting in a positional change of the optical element.

[0003] Patent Document 1 discloses a technology that can maintain the position of an optical element with high accuracy even when the optical element changes in the radial direction due to a change in external environment. [Prior Art Literature] [Patent Literature]

[0004] [Patent Document 1] Japanese Patent Laid-Open No. 2007-188010 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] However, Patent Document 1 may not be able to accurately hold the optical element in the direction rotating about the optical axis of the optical element. Therefore, when holding an optical element having non-rotationally symmetric characteristics, desired optical performance may not be achieved.

[0006] Accordingly, an object of the present invention is to provide a holding device that is advantageous for accurately holding an optical element. [Means for Solving the Problem]

[0007] To achieve the above objective, the holding device, as one aspect of the present invention, has a planar outer surface. And a second plane different from the aforementioned plane, A holding device for holding an optical element having the following contact surface And a second contact surface different from the contact surface that contacts the second plane, A lens barrel including the optical element and the optical axis of the optical element Before Press the recording optical element Furthermore, the optical element is positioned relative to the lens barrel with respect to the optical axis direction. The first elastic member and The optical element is pressed so that the plane contacts the contact surface, and the optical element is positioned relative to the lens barrel with respect to a direction intersecting the optical axis and an angle centered on the optical axis. The second elastic member and A third elastic member presses the optical element from a direction different from that of the second elastic member so that the second plane contacts the second contact surface, and positions the optical element with respect to the lens barrel in a direction intersecting the optical axis and at an angle centered on the optical axis, It is characterized by having the following features. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a holding device that is advantageous for accurately holding optical elements. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view of the holding device in the first embodiment. [Figure 2] This is an exploded view of the holding device in the first embodiment. [Figure 3] These are a side view and a front view of the holding device in the first embodiment. [Figure 4] This is a cross-sectional view of the holding device in the first embodiment. [Figure 5] This is a perspective view of the holding device in the second embodiment. [Figure 6] This is an exploded view of the holding device in the second embodiment. [Figure 7] These are a side view and a front view of the holding device in the second embodiment. [Figure 8] This is a cross-sectional view of the holding device in the second embodiment. [Figure 9] This is a schematic diagram showing the configuration of an exposure apparatus as one aspect of the present invention. [Figure 10] This is a schematic diagram showing the configuration of the illumination optical system. [Modes for carrying out the invention]

[0010] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In each drawing, the same members are denoted by the same reference numerals, and overlapping descriptions are omitted.

[0011] <First Embodiment> First, the holding device of the present embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a perspective view of a holding device 101. FIG. 2 is an exploded view of FIG. 1. FIG. 3(a) is a side view of the holding device 101, and FIG. 3(b) is a front view of the holding device 101. FIG. 4 is a cross-sectional view taken along line A-A shown in FIG. 3(a). In the present embodiment, the optical axis direction of the optical element 2 is defined as the Z direction, and directions perpendicular to the Z direction are defined as the X direction and the Y direction. In the present embodiment, the holding device 101 holds an optical element 2 (for example, a glass member such as a lens or an optical filter).

[0012] The holding device 101 includes a lens barrel 1, a spacer member 3, a leaf spring 4 (first elastic member), a screw 5, and a plunger 6 (second elastic member). The optical element 2 is pressed by the leaf spring 4 (first elastic member) via the annular spacer member 3, so that the optical element 2 is elastically held while being positioned in the Z direction (optical axis direction). The leaf spring 4 is fixed to the lens barrel 1 with the screw 5. A plurality of leaf springs 4 may be arranged along the circumferential direction of the optical element in order to stably hold the optical element 2.

[0013] The optical element 2 is pressed by the plunger 6 (second elastic member), so that the optical element 2 is elastically held while being positioned in the X direction and the θ direction (the angular direction centered on the optical axis) such that the contact surface 1a of the lens barrel 1 and the flat surface 2a of the optical element 2 are in contact with each other. Through holes are provided in the lens barrel 1, and the plunger 6 is arranged in each of the through holes. The number of the through holes and the plungers 6 may be singular or plural. The plunger 6 may be a ball plunger in which a ball at the tip operates, or a pin plunger in which a pin at the tip operates.

[0014] Furthermore, the optical element 2 in the present embodiment is a non-rotationally symmetric element having a flat surface 2a on its outer periphery. The contact between the contact surface 1a and the flat surface 2a can ensure that the optical element 2 does not rotate in the Z direction. In addition, the arrangement of the spacer member 3 allows the pressing force from the leaf spring 4 to be uniformized and transmitted to the optical element 2. Furthermore, since light is blocked by the spacer member 3 due to the arrangement thereof, the region where light is received by the optical element 2 can also be set to be an arbitrary region. The spacer member may have a perfectly circular opening. In addition, when performing elastic holding on the flat surface 2a, there is also an effect that holding is easier compared to a case where elastic holding is performed on a curved surface.

[0015] In the present embodiment, the contact surface 1a is a surface that plays a role of determining the position of the optical element 2 in the θ direction (the angular direction centered on the optical axis). The provision of the contact surface 1a makes it possible to prevent rotational displacement of the optical element 2 in the θ direction. Note that the optical element 2 may further have not only the flat surface 2a but also a curved surface on the outer periphery thereof.

[0016] Next, the pressing force applied to the optical element 2 by the leaf spring 4 and the plunger 6 will be described. Here, let F1 be the pressing force in the Z direction with which the leaf spring 4 presses the optical element 2. Let Fa be the frictional force in the X direction with which the leaf spring 4 presses the optical element 2. Let F2 be the pressing force in the X direction with which the plunger 6 presses the optical element 2. Let Fb be the frictional force in the Z direction with which the plunger 6 presses the optical element 2.

[0017] In the present embodiment, the elastic forces of the leaf spring 4 and the plunger 6 are set so that F1>Fb and F2>Fa are satisfied. That is, the elastic forces are set such that the pressing force applied to the optical element 2 by the second elastic member is stronger than the frictional force applied to the optical element 2 by the first elastic member, and the pressing force applied to the optical element 2 by the first elastic member is stronger than the frictional force applied to the optical element 2 by the second elastic member.

[0018] With the above settings, for example, even if the optical element 2 moves in the Z direction due to an impact during transport of the holding device 101 and the optical element 2, the pressing force F1 from the leaf spring 4 is greater than the frictional force Fb applied to the optical element 2, so the optical element 2 returns to its original position in the Z direction. Also, even if the optical element 2 moves in the X direction, the pressing force F2 from the plunger 6 is greater than the frictional force Fa applied to the optical element 2, so the optical element 2 returns to its original position in the X direction.

[0019] Therefore, according to this embodiment, even if the holding device 101 is affected by temperature changes or shocks during transport, the optical element 2 continues to be pressed against the lens barrel 1 by the leaf spring 4 and plunger 6. As a result, the optical element 2 can be positioned accurately without any looseness relative to the lens barrel 1. In other words, the holding device 101 can hold the optical element 2 with high precision.

[0020] <Second Embodiment> This embodiment describes an example in which each of the multiple planes provided on an optical element is elastically held by a plunger. Note that configurations not described in this embodiment are the same as in the first embodiment and are therefore omitted from description. Matters not mentioned in this embodiment follow those of the first embodiment.

[0021] The holding device 201 of this embodiment will be described with reference to Figures 5 to 8. Figure 5 is a perspective view of the holding device 201. Figure 6 is an exploded view of Figure 5. Figure 7(a) is a side view of the holding device 201, and Figure 7(b) is a front view. Figure 8 is a cross-sectional view of AA shown in Figure 7(a).

[0022] The optical element 2 is positioned and elastically held in the lens barrel 1 by a leaf spring 4 (first elastic member) and a plunger 6 (second elastic member). Furthermore, the optical element 2 is elastically held in the Y direction by a plunger 7 (third elastic member) such that the contact surface 1b (second contact surface) provided on the lens barrel 1 and the plane 2b (second plane) of the optical element 2 are in contact. In other words, the optical element 2 is elastically held in the X direction, Y direction and θ direction (angle direction around the optical axis) by the plunger 6 and plunger 7 and the contact surfaces 1a and 1b.

[0023] With the above configuration, even if the optical element 2 or the holding device 201 expands due to temperature changes, the optical element 2 continues to be pressed against the lens barrel 1 by the leaf spring 4, plunger 6, and plunger 7. Therefore, the optical element 2 does not become loose relative to the lens barrel 1, and the above-described positioning state is maintained.

[0024] Next, we will explain the pressing forces applied to the optical element 2 by the leaf spring 4, plunger 6, and plunger 7. Here, let F1 be the pressing force in the Z direction applied by the leaf spring 4 to the optical element 2. Let Fax be the frictional force in the X direction and Fay be the frictional force in the Y direction applied by the leaf spring 4 to the optical element 2. Let F2 be the pressing force in the X direction applied by the plunger 6 to the optical element 2. Let Fby be the frictional force in the Y direction and Fbz be the frictional force in the Z direction applied by the plunger 6 to the optical element 2. Let F3 be the pressing force in the Y direction applied by the plunger 7 to the optical element 2. Let Fcx be the frictional force in the X direction and Fcz be the frictional force in the Z direction applied by the plunger 7 to the optical element 2.

[0025] In this embodiment, the elastic forces of the leaf spring 4, plunger 6, and plunger 7 are set such that F1 > Fbz + Fcz, F2 > Fax + Fcx, and F3 > Fay + Fby. That is, in the Z direction, the pressing force on the optical element 2 by the first elastic member is set to be stronger than the sum of the frictional forces acting on the optical element 2. Also, in the X direction, the pressing force on the optical element 2 by the second elastic member is set to be stronger than the sum of the frictional forces acting on the optical element 2. Also, in the Y direction, the pressing force on the optical element 2 by the third elastic member is set to be stronger than the sum of the frictional forces acting on the optical element 2.

[0026] With the above settings, for example, even if the optical element 2 moves in the Z direction due to an impact during transport of the holding device 201 and the optical element 2, the pressing force F1 from the leaf spring 4 is greater than the frictional force Fbz + Fcz applied to the optical element 2. Therefore, the optical element 2 returns to its original position in the Z direction. Also, even if the optical element 2 moves in the X direction, the pressing force F2 from the plunger 6 is greater than the frictional force Fax + Fcx applied to the optical element 2, so the optical element 2 returns to its original position in the X direction. Also, even if the optical element 2 moves in the Y direction, the pressing force F3 from the plunger 7 is greater than the frictional force Fay + Fby applied to the optical element 2, so the optical element 2 returns to its original position in the Y direction.

[0027] Therefore, according to this embodiment, even if the holding device 201 is affected by temperature or transport shocks, the optical element 2 continues to be pressed against the lens barrel 1 by the leaf spring 4, plunger 6, and plunger 7. As a result, the optical element 2 can be positioned accurately without any looseness relative to the lens barrel 1. In other words, the holding device 201 can hold the optical element 2 with high precision.

[0028] The exposure apparatus 500 will be described below with reference to Figure 9. While the exposure apparatus is used as an example, any lithography apparatus that forms patterns on a substrate will suffice. The exposure apparatus 500 is used in the lithography process, a manufacturing process for semiconductor devices and liquid crystal display elements, to form patterns on a substrate. The exposure apparatus 500 exposes the substrate through a mask (master plate or reticle) and transfers the mask pattern to the substrate.

[0029] As shown in Figure 9, the exposure apparatus 500 includes an illumination optical system 510, a projection optical system 520, a mask stage 540 that holds and moves a mask 530, and a substrate stage 560 that holds and moves a substrate 550. Furthermore, the exposure apparatus 500 has a control unit 570 which is composed of a computer including a CPU and memory, and comprehensively controls each part of the exposure apparatus 500 to operate the exposure apparatus 500 according to a program stored in the memory unit.

[0030] As shown in Figure 10, the illumination optical system 510 includes multiple lenses 512, a fly-eye lens 513, a mirror 514, and other optical elements, and is an optical system that illuminates the mask 530 (the illuminated surface) with light from the light source LS. The fly-eye lens 513 is an optical system that homogenizes the light. An aperture diaphragm 515 is placed on the exit surface of the fly-eye lens, and an optical filter for forming an annular or quadrupole secondary light source may be placed there. For example, an annular diaphragm has a light-shielding portion that shields the elliptical center of the glass filter. When the light-shielding portion is elliptical, the position in the direction of rotation with respect to the optical axis of the glass filter is also important, so it is required to hold it with high precision in the angular direction by the holding device 101 or 201 described in each embodiment.

[0031] Since the illumination optical system 510 is located near the light source LS, the optical elements constituting the illumination optical system 510 and the holding device that holds such optical elements are subjected to thermal loads. Furthermore, although the optical elements may be transported while held in the holding device, there is a risk that they may be subjected to impact during transport, causing displacement. Therefore, the holding device 101 or 201 described in each embodiment is applied to the holding device that holds the optical elements constituting the illumination optical system 510. For example, the holding device 101 or 201 can be applied to hold the optical filter of the aperture diaphragm 515 in the illumination optical system 510.

[0032] The mask 530 is held on the mask stage 540. The mask 530 has a pattern formed on it that corresponds to the pattern to be formed on the substrate 550. The substrate 550 is held on the substrate stage 560. The mask 530 and the substrate 550 are positioned at optically nearly conjugate positions (the object plane and image plane of the projection optical system 520) via the projection optical system 520. The projection optical system 520 is an optical system that projects an object onto the image plane. Not only the reflective system shown in Figure 9, but also refractive systems and reflector-refracting systems can be applied to the projection optical system 520. In this embodiment, the projection optical system 520 has a predetermined projection magnification and projects the pattern formed on the mask 530 onto the substrate 550. The mask stage 540 and the substrate stage 560 are scanned in a direction parallel to the object plane of the projection optical system 520 (for example, the X direction) at a speed ratio corresponding to the projection magnification of the projection optical system 520. This allows the pattern formed on the mask 530 to be transferred to the substrate 550.

[0033] <Embodiment for manufacturing an article> The method for manufacturing articles according to embodiments of the present invention is suitable for manufacturing articles such as flat panel displays (FPDs), semiconductor devices, sensors, and optical elements. The method for manufacturing articles according to this embodiment includes a forming step (forming step) in which a pattern is formed on a substrate using the above-described lithography apparatus, and a processing step (processing step) in which the substrate on which the pattern has been formed in the forming step is processed. Furthermore, such a manufacturing method may include other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The method for manufacturing articles according to this embodiment is advantageous over conventional methods in at least one of the performance, quality, productivity, and production cost of the articles.

[0034] Although preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its gist. The holding device may be used, for example, to hold optical elements used in substrate processing equipment such as semiconductor manufacturing equipment (film deposition equipment, sputtering equipment, annealing equipment, etc.), organic EL deposition equipment, and nanoimprint equipment. [Explanation of Symbols]

[0035] 1 Telescope tube 1a Contact surface 2 Optical lenses 2a plane 4. Leaf spring (first elastic member) 6. Plunger (second elastic member) 101, 201 Holding device

Claims

1. A holding device for holding an optical element having a plane on its outer circumference and a second plane different from the aforementioned plane, A lens barrel including a contact surface that contacts the aforementioned plane and a second contact surface different from the aforementioned contact surface that contacts the second plane, A first elastic member presses the optical element in the direction of the optical axis and positions the optical element relative to the lens barrel with respect to the optical axis, A second elastic member presses the optical element so that the plane contacts the contact surface, and positions the optical element with respect to the lens barrel in a direction intersecting the optical axis and at an angle centered on the optical axis, A third elastic member presses the optical element from a direction different from the pressing direction of the second elastic member so that the second plane contacts the second contact surface, and positions the optical element with respect to the lens barrel in a direction intersecting the optical axis and at an angle centered on the optical axis, A holding device characterized by having the following features.

2. The holding device according to claim 1, characterized in that the pressing force applied by the third elastic member to the optical element is stronger than the frictional force applied by the first elastic member and the second elastic member to the optical element, and the pressing force applied by the first elastic member to the optical element is stronger than the frictional force applied by the second elastic member and the third elastic member to the optical element, and the pressing force applied by the second elastic member to the optical element is stronger than the frictional force applied by the first elastic member and the third elastic member to the optical element.

3. The holding device according to claim 1, characterized in that an annular spacer member is disposed between the optical element and the first elastic member.

4. The holding device according to claim 1, characterized in that a plurality of the second elastic members press against the plane.

5. The retaining device according to claim 1, characterized in that the first elastic member is a leaf spring.

6. The holding device according to claim 1, characterized in that the second elastic member and the third elastic member are plungers.

7. The holding device according to claim 1, characterized in that the holding device holds an optical filter provided with a light-shielding portion.

8. The optical element further includes a curved surface on its outer circumference, The holding device according to claim 1, characterized in that the lens barrel further includes a surface that contacts the curved surface.

9. A lithography apparatus for forming patterns on a substrate, An illumination optical system for illuminating a mask on which a pattern corresponding to the pattern to be formed on the substrate is formed, Includes a holding device, The illumination optical system includes optical elements, A lithography apparatus characterized in that the holding device includes a holding device according to any one of claims 1 to 8 for holding the optical element.

10. A forming step of forming a pattern on a substrate using the lithography apparatus described in claim 9, The process includes processing the substrate on which the pattern has been formed in the forming step, A method for manufacturing an article, characterized by manufacturing an article from the substrate processed in the above-mentioned processing step.

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