JP2013125790A - Holding device, exposure equipment, and device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a holding device advantageous in adjusting flatness of a pattern surface of an original plate.SOLUTION: The holding device for holding an original plate comprises: a plurality of chuck members which holds the original plate at an edge part of the original plate; and a plurality of support members, provided for the plurality of respective chuck members, which holds the plurality of chuck members, wherein each of support members is so constituted that its thickness is adjustable.

Description

  The present invention relates to a holding apparatus that holds an original plate, an exposure apparatus having the holding apparatus, and a device manufacturing method using the exposure apparatus.

  Devices represented by liquid crystal display elements and semiconductor elements can be manufactured by photolithography. An exposure apparatus used for this photolithography includes an original stage that holds and moves an original (mask or reticle), and a substrate stage that holds and moves a substrate (plate or wafer). Then, the positions of the original stage and the substrate stage are controlled, and the substrate is exposed through the original and the projection optical system.

  The exposure apparatus includes a batch exposure type that collectively transfers a pattern formed on an original to a substrate and a scanning exposure that continuously transfers the pattern of the original to the substrate while synchronously scanning the original stage and the substrate stage. There are some types. In any apparatus, it is necessary that the flatness of the pattern surface of the original plate and the flatness of the surface of the substrate are within an allowable range determined from the depth of focus of the projection optical system. Therefore, with respect to the surface of the substrate, the flatness of the substrate holding surface is adjusted to be within an allowable range by inserting a foil under the substrate holding member.

  Further, with respect to the original plate, a holding member (chuck member) cannot be disposed in an area through which exposure light passes. Therefore, the original plate is held by using a chuck that holds the outer peripheral portion of the original plate, which is a single product and has a guaranteed flatness. Moreover, the flatness of the pattern surface of the mask is within an allowable range by providing a flatness correction mechanism that reduces the bending due to the weight of the mask by making the space adjacent to the upper surface of the original negative pressure (Patent Document 1). ).

JP 2006-135085 A

  The flatness required for the pattern surface of the original plate has increased due to the enlargement of the original plate accompanying the expansion of the exposure area in recent years and the reduction of the depth of focus accompanying the increase in the resolution, and it has become difficult to satisfy it. In order to improve the flatness of the pattern surface, it is necessary to use the flatness correction mechanism as described above and to secure the flatness of the upper surface of the chuck over a wide area. However, the chuck has a flat structure with a single member, especially in the case of holding an enlarged original plate in recent years, because it is necessary to provide an opening for allowing exposure light to pass inside. Difficult to do.

  Another problem is that the temperature of the pattern surface of the original plate and the upper surface of the chuck changes due to the influence of heat caused by exposure energy and drive energy, which affects the flatness of the pattern surface.

  Although there is a method of adjusting the flatness of the chuck upper surface by inserting the foil as described above, it is not preferable from the viewpoint of component cost and adjustment number. Further, such an adjustment method is difficult to cope with a change in flatness of the pattern surface and the chuck upper surface due to the influence of heat.

  Therefore, an object of the present invention is to provide a holding device that is advantageous for adjusting the flatness of the pattern surface of the original plate.

One aspect of the present invention is a holding device for holding an original,
A plurality of chuck members for holding the original at the edge of the original;
A plurality of support members provided for each of the plurality of chuck members, and supporting the plurality of chuck members;
Have
Each of the plurality of support members is configured such that its thickness can be adjusted.
This is a holding device.

  According to the present invention, for example, it is possible to provide a holding device that is advantageous for adjusting the flatness of the pattern surface of an original.

It is a figure which shows the structure containing the chuck member and support member in a holding | maintenance apparatus. It is a figure which shows the structure of exposure apparatus. It is a figure which shows the structural example of a holding | maintenance apparatus. It is a figure which shows the structural example for adjusting the thickness of a supporting member.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that, in principle, the same members are denoted by the same reference symbols throughout the drawings, and repeated description thereof is omitted.

[Embodiment 1]
FIG. 1 is a diagram showing a structure including a chuck member and a support member in a holding device that holds a mask (original plate or reticle). In FIG. 1, (a) is an overhead view, and (b) is an overhead view. As shown in FIG. 1A, the mask 23 is mounted on the chuck 24, and the mask 23 is vacuum-sucked on the chuck 24. Here, in FIG. 1, the chuck 24 includes four chuck members 24 a to 24 d that respectively hold four positions adjacent to the four sides of the mask outer shape. However, the present invention is not limited to this, and the number of chuck members may be plural (having an effect of flatness correction). In addition, by increasing the number of chuck members, the flatness processing of the upper surface of each chuck member can be facilitated, and the manufacturing cost can be reduced.

  Each chuck member includes two wedge-shaped members stacked, and at least one of the two wedge-shaped members is supported by three support members 25 configured to be movable with respect to the other. The thickness of the support member 25 can be adjusted by the relative movement of the two wedge-shaped members. The three support members 25 are not arranged on the same straight line. Thereby, by adjusting the thicknesses of the three support members 25, the height and inclination of the upper surface can be adjusted without substantially distorting the chuck member. The thickness adjusting mechanism preferably includes an actuator (drive unit) and can be remotely operated or automatically controlled. Although each chuck member is supported by the three support members 25, the present invention is not limited to this. That is, providing at least one support member 25 for each chuck member has an effect of correcting the flatness of the upper surface of the chuck 24. For example, when only one support member 25 is provided for each chuck member, the flatness of the upper surface of the chuck 24 can be improved by adjusting the height of each of the four chuck members 24a to 24d. The same applies to the case where only two support members 25 are provided for each chuck member (because the inclination of each chuck member can be adjusted, the effect of improving the flatness can be increased compared to the case where only one support member 25 is provided). When four or more support members 25 are provided for each chuck member, the plane is generally determined by three points. Therefore, the flatness of the upper surface of the chuck member may be adjusted by the thickness of the three support members 25. In addition, the thickness of the other one or more support members 25 may be adjusted to a thickness that does not impair the flatness. In this case, since the number of supporting points for supporting the chuck member is increased, there is an effect of reducing bending due to the weight of the chuck member.

  Using the configuration as described above, the height and inclination of the upper surface of each chuck member is adjusted so that the entire upper surface of the chuck 24 forms a single plane, so that the pattern surface of the mask can be easily and at low cost. Flatness can be kept within an allowable range. In addition, when the thickness adjusting mechanism includes a drive unit, as will be described later, it is possible to remotely control or automatically control the flatness correction of the mask pattern surface by further including a measuring instrument that measures the shape of the mask surface. Can do.

  Here, a scanning exposure apparatus to which the present invention is applied will be described with reference to FIG. FIG. 2 is a view showing the arrangement of the exposure apparatus according to this embodiment. A mask stage (original stage) 20 is disposed on the upper side in the Z-axis direction with the projection optical system 10 interposed therebetween, and a plate stage (substrate stage) 30 is disposed on the lower side. The mask stage 20 and the plate stage 30 are individually movable, and their positions are measured by a position measuring device 50 such as a laser interference length measuring device. The mask stage 20 and the plate stage 30 are each positioned and controlled based on the measurement result of the position measuring device 50 by an actuator (not shown) provided in the exposure apparatus.

  The plate stage 30 has a Y stage 32 and an X stage 33 disposed on the main body base 31. Note that the X direction and the Y direction are orthogonal to each other. A θZ stage 34 is mounted on the XY stage, and a plate chuck 35 is disposed thereon, whereby a plate (substrate) 36 to be exposed is held. Accordingly, the plate 36 can be moved in the X, Y, and Z axis directions by the plate stage 30 and can be rotated around each axis. The θZ stage 34 is for aligning the surface of the plate 36 with the focal plane of the projection optical system 10 (image side) (within the depth of focus).

  The mask stage 20 includes a mask stage base 21 disposed on a surface plate (not shown) and a chuck 24 disposed thereon, and a pattern to be projected onto the plate 36 on the chuck 24. A mask 23 having the following is arranged. Here, the mask 23 can be moved in the X and Y directions by the movable mask stage base 21 and can be rotated around the X and Y axes. Above the mask stage 20, an alignment measurement optical system 40 for measuring the relative position between the mark image formed on the mask 23 and the mark image formed on the plate 36 via the projection optical system 10. (Advancing and retracting with respect to the optical path) is arranged. Further above that, an illumination optical system 41 for illuminating the mask is arranged.

  As described above, the position of the mask stage 20 and the plate stage 30 is measured and controlled using the position measuring device 50. In FIG. 2, the position measuring device 50 is a laser interference length measuring device, and is disposed on the laser head 51, the beam splitter 52, the reflector 53, the reflector 54 disposed on the θZ stage 34, and the mask stage base 21. The reflector 55 is provided. Here, the position of the laser beam of the laser interferometer is the mask stage (the optical axis of the projection optical system 10) with respect to the mask stage 20, or the mask side (object side) focal plane of the projection optical system 10 or its vicinity. Is arranged. Further, it is arranged at or near the optical axis position of the projection optical system 10 in the X-axis direction. Further, the plate stage 30 is disposed at or near the optical axis position of the projection optical system 10 in the X-axis direction.

  FIG. 3 is a diagram illustrating a configuration example of the holding device according to the present embodiment. The mask 23 is held by a chuck 24 supported by a support member 25. Here, the mask 23 can be adsorbed on the upper surface of each chuck member by exhausting exhaust holes or exhaust grooves (not shown) formed on the upper surfaces of the chuck members (24a to 24d). However, the attachment of the mask by each chuck member is not limited to vacuum suction, and may be based on other principles such as electrostatic force, magnetic force, or mechanical fixation. In addition, since the chuck member cannot be disposed below the central portion of the mask 23 (the region where light should be transmitted), the flatness correcting mechanism 62 (the pressure reducing mechanism is not shown) described above causes the mask to bend due to its own weight. Reduced.

  In FIG. 3, reference numeral 60 denotes a sensor that constitutes a measuring instrument that measures the shape of the surface of the mask. For example, in order to measure the shape (flatness) of the lower surface (pattern surface) of the mask, it is a sensor (detector) that detects the position of the lower surface. Here, the sensor 60 is attached to, for example, the upper surface or the side surface of the housing of the projection optical system 10 close to the mask 23 to be measured. In order to measure the shape of the pattern surface, for example, the position of the pattern surface in the Z-axis direction is measured once or a plurality of times by a fixed sensor 60 in parallel with the movement of the mask stage 20 in the Y-axis direction. Good. If a plurality of sensors 60 are arranged in the X-axis direction, the shape of the pattern surface can be measured efficiently. As the sensor 60, a sensor that detects the position of reflected light obtained by projecting light onto the pattern surface, a sensor that detects capacitance, and the like, are used between the pattern surface and the reference surface. A method of measuring distance can be used. However, the present invention is not limited to this, and any material that can be used for measuring the shape (flatness) of the pattern surface may be used.

  In FIG. 3, reference numeral 61 denotes a calculation unit which is used to obtain the shape of the pattern surface based on the position information and position information group of the pattern surface detected by the sensor 60. Furthermore, the calculating part 61 calculates | requires the plane (approximate plane) which approximates the shape of the calculated | required pattern surface, for example. Then, it is possible to generate a command value that reduces the inclination of the approximate plane with respect to the target plane (target plane). The command value may be a command value that reduces the inclination of the approximate plane with respect to the XY plane, for example. The calculating unit 61 can control the thickness adjusting mechanism (described later) and the flatness correcting mechanism 62 of the support member 25 according to the command value, and can correct the flatness (shape) of the mask 23. In this case, the calculation unit 61 constitutes a measuring instrument that measures the shape (flatness) of the surface of the mask, and a thickness adjusting mechanism (an actuator described later) based on the shape (flatness) measured by the measuring instrument. ) And a control unit for controlling the flatness correcting mechanism 62. The calculation unit 61 is not limited thereto, but may include, for example, a computer (or CPU or MPU) that operates according to a program, an FPGA (Field-Programmable Gate Array), or the like.

  The flattening described above may be performed, for example, when the mask held by the chuck 24 is replaced. When the mask is replaced, the measurement of the shape (flatness) of the mask surface may be performed by the measuring instrument, and the flattening may be performed. Alternatively, the substrate exposed through the mask held by the chuck 24 may be replaced. When the plate is exchanged, the measurement of the shape (flatness) of the mask surface may be performed by the measuring instrument, and the flattening may be performed. However, the conditions or timing for performing flattening are not limited to these, and can be set as necessary. In this way, it is possible to reduce the variation (deviation from the allowable range) in the shape (flatness) of the pattern surface of the mask associated with the operating state of the exposure apparatus and changes with time.

  FIG. 4 is a diagram illustrating a configuration example (of the thickness adjusting mechanism) for adjusting the thickness of the support member 25. As shown in FIG. 1, a support member 25 is disposed below the chuck 24. The support member 25 includes a wedge-shaped member (upper) 70, a wedge-shaped member (lower) 71, a base plate 72, and an adjustment screw 73. In FIG. 4, reference numeral 74 denotes an actuator (driving unit, for example, a motor) for turning the adjusting screw 73. Here, by turning the adjustment screw 73, the wedge-shaped member (lower) 71 moves on the base plate 72 in the axial direction (X-axis direction) of the adjustment screw. Then, since the wedge-shaped member (upper) and the wedge-shaped member (lower) are laminated, the movement of the wedge-shaped member (lower) in the X-axis direction is converted into the movement of the wedge-shaped member (upper) in the Z-axis direction. Thereby, the thickness of the support member 25 can be adjusted, and thus the height and inclination of the chuck 24 are adjusted by adjusting the height and inclination (or only the height) of each chuck member (24a to 24d). can do. It should be noted that the sensitivity or resolution when adjusting the thickness of the support member 25 can be set by the size of the wedge angle of the wedge-shaped member, for example. The thickness adjusting mechanism for adjusting the thickness of the support member 25 uses, for example, a hydraulic drive system, a piezoelectric element, a linear motor, or the like, instead of the one including the above-described stacked wedge members. As long as the required specifications can be satisfied, it is not particularly limited to the above.

[Embodiment 2]
A method for manufacturing a device (semiconductor device, liquid crystal display device, etc.) according to an embodiment of the present invention will be described. A semiconductor device is manufactured, for example, through a pre-process for producing an integrated circuit on a wafer (substrate) and a post-process for completing the integrated circuit on the wafer produced in the pre-process as a product. The pre-process includes a step of exposing the wafer coated with the photosensitive agent using the above-described exposure apparatus, and a step of developing the exposed wafer. The post-process includes an assembly process (dicing and bonding) and a packaging process (encapsulation). A liquid crystal display device is manufactured by passing through the process of forming a transparent electrode, for example. The step of forming a transparent electrode includes a step of applying a photosensitive agent to a glass substrate on which a transparent conductive film is deposited, a step of exposing the glass substrate on which the photosensitive agent is applied using the above-described exposure apparatus, and a glass Developing the substrate. The method for manufacturing an article according to the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article as compared with the conventional method.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

24a-24d Chuck member 25 Support member 70 Wedge member (upper)
71 Wedge member (bottom)
72 Base plate 73 Adjustment screw

Claims (11)

A holding device for holding an original plate,
A plurality of chuck members for holding the original at the edge of the original;
A plurality of support members provided for each of the plurality of chuck members, and supporting the plurality of chuck members;
Have
Each of the plurality of support members is configured such that its thickness can be adjusted.
A holding device. A plurality of actuators that are provided for each of the plurality of support members and that respectively adjust the thicknesses of the plurality of support members;
The holding device according to claim 1.   The holding device according to claim 1, wherein the plurality of chuck members include at least four chuck members.   4. The support member according to claim 1, wherein at least three support members among the plurality of support members are provided for each of the plurality of chuck members. 5. Holding device.   Each of the plurality of supporting members includes two stacked wedge-shaped members, and at least one of the two wedge-shaped members is configured to be movable with respect to the other. 5. The holding device according to any one of 4 above. A measuring instrument for measuring the shape of the surface of the original,
A control unit for controlling the actuator based on the shape measured by the measuring instrument;
The holding device according to claim 2, further comprising:   The said control part calculates | requires the approximate plane which approximates the said shape measured by the said measuring device, and controls the said actuator so that the inclination of the said approximate plane with respect to the target plane may reduce. Item 7. The holding device according to Item 6. An exposure apparatus that exposes a substrate through an original plate,
The holding device according to any one of claims 1 to 7, which holds the original plate.
An exposure apparatus comprising:   The exposure apparatus according to claim 8, wherein the control unit causes the measuring instrument to measure the shape when an original held by the plurality of chuck members is replaced.   The said control part makes the said measuring device measure the said shape, when the board | substrate exposed through the original plate hold | maintained by these several chuck members is replaced | exchanged, The said measurement part is characterized by the above-mentioned. Item 10. The exposure apparatus according to Item 9. A step of exposing the substrate using the exposure apparatus according to any one of claims 8 to 10,
Developing the substrate exposed in the step;
A device manufacturing method comprising:

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