JPH0794402A - Positioning device - Google Patents

Abstract

PURPOSE:To reduce the heat resistance between mechanism members so as to make the temperature changes of members constituting a positioning mechanism system and positioning errors caused by thermal deformation smaller by enclosing a fluid having high heat conductivity in a space between the members constituting a positioning device. CONSTITUTION:A guide table 2 is fixed on a stool 1. Such a fluid 202 as mercury, helium, etc., having high heat conductivity is enclosed in a space between the stool 1 and table 2 by using a sealing material 201. As a result, the thermal contact resistance between the stool 1 and table 2 is reduced. Even when frictional heat, etc., is supplied to the table 2, in addition, the frictional heat, etc., is readily transferred to the stool 1, because the stool 1 is thermally stabilized due to a large heat capacity the stool 1 has and can be relatively easily controlled in temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a reduction projection exposure apparatus, an X-ray exposure apparatus, an electron beam drawing apparatus, etc. used in a semiconductor lithography process, and has a small temperature change of members and a positioning error due to thermal deformation. Regarding the device.

[0002]

2. Description of the Related Art In a semiconductor lithography process, in order to form a high-definition pattern, it is required to position a sample such as a wafer with high accuracy. Thermal deformation of the sample and the positioning mechanism system is a factor that deteriorates the positioning accuracy. Therefore, Japanese Patent Laid-Open No. 60-158626 is known as a conventional technique for suppressing the temperature change of the sample and the positioning mechanism system. This is as shown in FIG.
A heat exchange medium flow path 1202 is provided in 201, and the heat exchange medium 1204 whose temperature is controlled by the temperature control device 1203 is circulated.

[0003]

However, in the prior art, it is necessary to install a temperature control device for the heat exchange medium and a pipe for circulating the heat exchange medium in the movable part, which is mechanically complicated. There is a problem that it becomes.

An object of the present invention is to reduce the thermal resistance between the mechanical members, to promote heat transfer to a surface plate which is thermally stable because of its large heat capacity and whose temperature control is relatively easy. Accordingly, it is an object of the present invention to provide a positioning device in which the temperature change of the members constituting the positioning mechanism system is small and the positioning error due to thermal deformation is small.

[0005]

In the present invention, a fluid having a high thermal conductivity is sealed in the contact portion between the members constituting the positioning device. (Claim 1) Further, according to the present invention, a concave portion or a convex portion is provided in a contact portion between members constituting the positioning device, and a fluid having a high thermal conductivity is enclosed. (Claim 2) In the present invention, a fluid having a high thermal conductivity is used as the viscous fluid for the squeeze damper that constitutes the positioning device. (Claim 3) Furthermore, in the present invention, one member constituting the positioning device is provided with a sealed fluid tank, and the other member is brought into contact with the fluid in the fluid tank.

[0006]

[Function] The thermal resistance between the mechanical members is reduced and the heat capacity is large, so that it is thermally stable, and even when temperature control is required, it is relatively easy to install a heat exchange medium pipe or the like. By promoting heat transfer to the board, it is possible to obtain a positioning device in which the temperature change of the member is small and the positioning error due to thermal deformation is small.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing the outline of an embodiment of a positioning device of the present invention. A guide 2 is fixed on the surface plate 1. The moving table 4 is driven in the X-axis direction by the actuator 9, and the sliding portion 3 fixed to the moving table 4 slides on the guide table 2. The heat radiating portion 6 fixed to the moving table 4 is brought into contact with the fluid having high thermal conductivity in the fluid tank 5. The fluid in the fluid tank 5 is sealed by the cover 8. The cover 8 is movable in the X-axis direction and moves together with the heat dissipation unit 6 on the fluid tank. The cover 8 is pressed against the heat dissipation portion 6 by the pressing device 7,
The fluid in the fluid layer 5 is always sealed.

FIG. 2 is a sectional view showing an embodiment of a method of fixing the guide base 2 to the surface plate 1 in the positioning device of the present invention. A fluid 202 having a high thermal conductivity, such as mercury or helium, is enclosed between the surface plate 1 and the guide base 2 by using a sealing material 201. Generally, when members are brought into contact with each other, the true contact area between them is said to be about one thousandth of the apparent contact area. The heat transfer between the members placed in the vacuum is only the heat conduction at a slight real contact portion and the radiation in the gap between the members, so that the contact thermal resistance between the members becomes very large.
Therefore, by adopting the fixing method as described above, the contact thermal resistance between the surface plate 1 and the guide table 2 is reduced, and even when friction heat or the like is supplied to the guide table 2, the heat capacity is large and thermally stable. The heat transfer to the surface plate 1 whose temperature control is relatively easy is promoted. Therefore, the temperature change of members such as the guide table 2 and the moving table (not shown) is suppressed.

FIG. 3 is a sectional view showing a second embodiment of a method of fixing the guide table 2 to the surface plate 1. A fluid 202 having high thermal conductivity is sealed between the surface plate 1 and the guide base 2 by using a sealing material 201. At this time, the guide stand 2 is provided with the guide stand convex portion 301. As a result, the layer of the fluid 202 can have an optimum thickness regardless of the diameter of the sealing material 201, and the contact thermal resistance between the surface plate 1 and the guide base 2 can be further reduced.

FIG. 4 is a sectional view showing a third embodiment of a method of fixing the guide table 2 to the surface plate 1. A fluid 202 having high thermal conductivity is sealed between the surface plate 1 and the guide base 2 by using a sealing material 201. At this time, the guide board 2 is provided with the guide board uneven portion 401
a, 401b, 401c are provided, and the surface plate 1 is provided with surface plate uneven portions 402a, 402b, 402c. As a result, the layer of the fluid 202 can have an optimum thickness regardless of the diameter of the sealing material 201, and the heat transfer area through the fluid 202 can be large, so that the surface plate 1 and the guide table 2 can be in contact with each other. The thermal resistance can be further reduced. The shapes of the guide table uneven portion 401 and the surface plate uneven portion 402 are the same as those of the fluid 202.
It suffices that a large heat transfer area can be obtained through, and more irregularities may be provided or a curved surface may be used.

Other members may be fixed by using the method of fixing the surface plate 1 and the guide base 2 shown in FIGS. 2, 3 and 4. For example, in FIG. 1, the same method can be used for fixing the sliding unit 3 and the moving table 4 or fixing the moving table 4 and the heat radiating unit 6. As a result, even when heat is supplied to the moving table 4, the contact thermal resistance of each part is small, so that the surface plate 1
Since heat transfer to the moving table 4 is promoted, it is possible to suppress the temperature change of the moving table 4.

FIG. 5 is a sectional view showing an embodiment of a sliding portion in the positioning device of the present invention. As the sliding portion 6, a viscoelastic guide having a structure as shown in FIG. 5 that has both a viscous damping effect and an elastic supporting function is known. The sliding portion 6 to which the sliding member 504 is attached slides on the guide base 2 in the X-axis direction. When the movable table 4 is stopped, the movable table 4 is elastically supported by the elastic hinge 502 in the X-axis direction with respect to the guide table 2. On the other hand, due to the squeeze effect of the viscous fluid 503 enclosed by the O-ring 501, the moving table 4 is structured to receive a damping force. In the present invention, a viscous fluid 503 having a high thermal conductivity such as mercury is used.
Thereby, the thermal resistance from the moving table 4 to the guide table 2 via the sliding portion 6 is reduced.

FIG. 6 is a sectional view showing an embodiment of a heat radiating section in the positioning device of the present invention. Fluid tank 5 on surface plate 1
And a fluid 602 having a high thermal conductivity is provided to the sealing material 6
It is enclosed by 01. Heat dissipation part 6 fixed to the moving table 4
Contacts the fluid 602. As a result, heat transfer from the moving table 4 to the surface plate 1 via the heat radiating portion 6 is promoted, and the moving table 4
Temperature change is suppressed.

FIG. 7 is a perspective view showing an embodiment of a cover in the positioning device of the present invention. The heat dissipation part 6 moves in the X-axis direction together with a moving table (not shown). At this time, an external force F is applied to the covers 8a and 8b and is constantly pressed against the heat radiating portion 6, so that the fluid in the fluid tank 5 provided on the surface plate 1 is constantly sealed.

FIG. 8 is a plan view showing an embodiment of a pressing device in the positioning device of the present invention. Cover 8a,
A telescopic tube 801 capable of expanding and contracting in the X-axis direction is provided at the end of 8b.
Attach a and 801b. Telescopic tubes 801a, 801b
Is connected to a tube 802, which creates a closed space inside.
A fluid having a higher pressure than the atmosphere is sealed inside the expansion tubes 801a and 801b and the tube 802. As a result, the pressing force F always acts on the ends of the covers 8a and 8b,
Since the covers 8a and 8b are pressed against the heat dissipation part 6 regardless of the position of the heat dissipation part 6, a fluid tank (not shown)
The sealed state of the fluid inside is maintained. Therefore, even when the positioning device is placed in a vacuum, the fluid can be prevented from scattering and the fluid tank can be provided.

In the above, the embodiment of the positioning device movable only in the X-axis direction has been described, but in FIG. 1, members movable in other axial directions are stacked on the moving base 4. Thereby, a positioning device having space 6 degrees of freedom is obtained. The structure shown in FIGS. 2 to 8 may be applied to the members stacked on the moving table 4.

FIG. 9 is a perspective view showing an embodiment of the reduction projection exposure apparatus of the present invention. The light emitted from the illumination system 901 passes through the reticle 902 on which a circuit pattern is drawn,
An image of the circuit pattern is formed on the wafer 905 which is reduced by the reduction lens 903 and mounted on the positioning device 904 of the present invention. According to the reduction projection exposure apparatus, the heat generation and positioning apparatus 90 by the exposure of the wafer 905 is exposed.
Since the temperature change of the constituent members of the positioning device 904 and the wafer 905 due to the influence of heat generated from the actuator in 4 and frictional heat is small and thermal deformation is suppressed, highly accurate alignment between the circuit pattern and the wafer 905 can be achieved. It can be performed.

FIG. 10 is a perspective view showing an embodiment of the X-ray exposure apparatus of the present invention. The X-ray emitted from the X-ray source 1001 passes through the X-ray illumination system 1002, is reflected by the mask 1003 on which the circuit pattern is drawn, is reduced by the image forming system 1004, and is mounted on the positioning device 1005 of the present invention. An image of the circuit pattern is formed on the wafer 1006. According to the X-ray exposure apparatus, the temperature change of the components of the positioning apparatus 1005 and the wafer 1006 due to the heat generated by the exposure of the wafer 1006, the heat generated from the actuator in the positioning apparatus 1005, the frictional heat, and the like are small, Since the thermal deformation is suppressed, the circuit pattern and the wafer 1006 can be aligned with high accuracy.

FIG. 11 is a perspective view showing an embodiment of the electron beam drawing apparatus of the present invention. The electron beam emitted from the electron gun 1101 is a beam diameter variable optical system 1102 and a blanking system 11
The wafer 1 that has passed through 03, is deflected by the converging polarization system 1104, and is mounted on the positioning device 1105 of the present invention.
106 is illuminated. According to the present electron beam drawing apparatus, the temperature change of the constituent members of the positioning device 1105 and the wafer 1106 due to the effects of heat generated by the electron beam applied to the wafer 1106, heat generated from the actuator in the positioning device 1105, frictional heat, and the like. Since it is small and thermal deformation is suppressed, highly accurate alignment between the circuit pattern and the wafer 1106 can be performed.

[0021]

EFFECTS OF THE INVENTION Heat transfer to a surface plate, which reduces thermal resistance between mechanical members and is thermally stable due to its large heat capacity, and whose temperature control is relatively easy by installing a heat exchange medium pipe or the like. By accelerating the above, it is possible to obtain the positioning device in which the temperature change of the member is small.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a positioning device of the present invention.

FIG. 2 is a cross-sectional view for explaining an example of a method of fixing the guide table to the surface plate in the positioning device of the present invention.

FIG. 3 is a cross-sectional view for explaining a second embodiment of a method of fixing the guide table to the surface plate in the positioning device of the present invention.

FIG. 4 is a cross-sectional view for explaining a third embodiment of a method of fixing the guide table to the surface plate in the positioning device of the present invention.

FIG. 5 is a cross-sectional view of an example of a sliding portion in the positioning device of the present invention.

FIG. 6 is a cross-sectional view of an embodiment of a heat radiating portion in the positioning device of the present invention.

FIG. 7 is a perspective view of an embodiment of a cover in the positioning device of the present invention.

FIG. 8 is a plan view of an embodiment of a pressing device in the positioning device of the present invention.

FIG. 9 is a perspective view of an embodiment of a reduction projection exposure apparatus of the present invention.

FIG. 10 is a perspective view of an example of the X-ray exposure apparatus of the present invention.

FIG. 11 is a perspective view of an embodiment of the electron beam drawing apparatus of the present invention.

FIG. 12 is an explanatory diagram of a conventional positioning device.

[Explanation of symbols]

1 ... Surface plate, 2a, 2b ... Guide stand, 3a, 3b ... Sliding part,
4 ... moving table, 5 ... fluid tank, 6 ... radiating section, 7a, 7b ... pressing device, 8a, 8b ... cover, 9 ... actuator.

Claims (1)

[Claims] 1. A positioning device, characterized in that a fluid having a high thermal conductivity is sealed in a contact portion between members constituting a positioning mechanism system.