Electrical generator or motor structure – Dynamoelectric – Linear
Reexamination Certificate
2000-07-27
2002-02-26
Ramirez, Nestor (Department: 2834)
Electrical generator or motor structure
Dynamoelectric
Linear
C356S936000, C355S072000
Reexamination Certificate
active
06351041
ABSTRACT:
INCORPORATION BY REFERENCE
The disclosure of the following priority application is herein incorporated by reference:
Japanese Patent Application No. 11-2152273 filed Jul. 29, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to stage apparatus for positioning a sample with high precision within a two-dimensional plane, and an inspection apparatus having the stage apparatus.
2. Description of the Related Art
Conventional stage apparatus are used with exposure apparatus for manufacturing semiconductor devices etc. using lithographic processes, inspection apparatus for inspecting circuit patterns formed on the semiconductor devices, and with ultraprecise manufacturing apparatus, and are used to position samples such as wafers, etc. within a two-dimensional plane in a highly-precise manner.
For example, as shown in
FIG. 21
, a magnetic levitation-type stage apparatus
200
disclosed in Japanese Patent Laid-open Publication No. Hei. 9-17846 comprises a rectangular fixed stage
211
and a rectangular moving stage
212
smaller than the fixed stage
211
and the sample is mounted on the moving stage
212
. The fixed stage
211
comprises a multiplicity of magnets
213
arranged in longitudinal and lateral direction, and a sealed tank
214
for housing the magnets
213
. An upper plate of the sealed tank
214
is made of a material with a low permeability. Six permanent magnets
215
and three gap sensors
216
are fitted to the bottom surface of the moving stage
212
levitated above the fixed stage
211
. The three gap sensors
216
measure the position of the moving stage
212
in a direction Z and inclination in directions &agr; and &bgr;, taking the upper plate of the sealed tank
214
as a reference.
Three laser interferometers
217
are provided about the periphery of the fixed stage
211
. The three laser interferometers
217
measure the position of the moving stage
212
in directions X and Y, and inclination in a direction &thgr;.
The magnets
213
and the permanent magnets
215
constitute a planar motor. Attractive force, repulsion, and Lorentz's force are generated by supplying current to the magnets
213
of the planar motor so that the moving stage
212
can be driven.
At the stage apparatus
200
, control apparatus (not shown) receiving information from the gap sensors
216
and the laser interferometers
217
controls the current of the magnets
213
so as to drive the moving stage
212
to the desired position and posture. The position of samples such as wafers etc. mounted on the moving stage
212
can therefore be decided with six degrees of freedom in the direction X, Y, Z, &thgr;, &agr; and &bgr;.
Degassification from the magnets
213
is prevented because the magnets
213
are housed within the sealed tank
214
and the stage apparatus
200
can therefore be employed not just in the atmosphere, but can also operate in clean rooms and in a vacuum.
On the other hand, as shown in
FIG. 22
, with a stage apparatus
300
disclosed in Japanese Patent Laid-open Publication No. Hei. 3-73513, slide sections
301
x
and
301
y
are moved along guide rails
302
x
and
302
y
by drive screws
303
x
and
303
y
, with the guide rail
302
y
being fixed to the slide section
301
x.
At the slide sections
301
x
and
301
y
, supply pipes
304
x
and
304
y
for supplying high-pressure gas (dry air) are connected to a gap between the slide sections
301
x
and
301
y
and the guide rails
302
x
and
302
y.
Gas exhaust sections
309
x
and
309
y
are fitted to the slide sections
301
x
and
301
y
and are connected to exhaust pipes
310
x
and
310
y
linked to a vacuum pump (not shown).
At the stage apparatus
300
, high-pressure gas supplied from the supply pipes
304
x
and
304
y
to the gap between the slide sections
301
x
and
301
y
and the guide rails
302
x
and
302
y
then flows in the direction of a gap between the gas exhaust sections
309
x
and
309
y
and the guide rails
302
x
and
302
y
and is discharged rapidly to outside of the vacuum chamber via the exhaust pipes
310
x
and
310
y.
The slide sections
301
x
and
301
y
(and the gas exhaust sections
309
x
and
309
y
) therefore move in directions X and Y while being levitated from the guide rails
302
x
and
302
y
. A sample
313
is mounted at a table
308
on the slide section
301
y.
With the stage apparatus
300
where bearings for X and Y-directions are static pressure gas bearing slides, high pressure gas for levitating the slide sections
301
x
and
301
y
(gas exhaust sections
309
x
and
309
y
) from the guide rails
302
x
and
302
y
is released to the outside of the vacuum chamber and use in a vacuum or special gas is possible.
However, with the magnetic levitation-type stage apparatus
200
(
FIG. 21
) described above, all positions and postures of the moving stage
212
have to be simultaneously controlled by the planar motor constituted by the magnets
213
and the permanent magnets
215
(control of six axes) and it is necessary to drive the multiplicity of magnets
213
independently, which requires an extremely complex control system.
Cables (not shown) etc. fitted to the moving stage
212
are influence by pulling force and vibrations (disturbances) and it is therefore difficult to exert control in such a manner that inter-axial interference does not occur, even with a complex control system. This puts a limit on the extent to which positioning precision can be improved with the related stage apparatus
200
.
With the stage apparatus
300
(
FIG. 22
) provided with the static pressure gas bearings, the exhaust pipes
310
x
and
310
y
are constituted by metal bellows-like members which ensure that the exhaust pipes
310
x
and
310
y
while at the same time ensuring that the exhaust pipes
310
x
and
310
y
extend and contract. However, it is difficult to smoothly extend and contract according to movement of the slide sections
301
x
and
301
y.
There are therefore cases where unnecessary reactive force is applied to the slide sections
301
x
and
301
y
from the metal bellows-like members when the slide sections
301
x
and
301
y
move and this places limitations on the extent to which positioning precision can be improved.
SUMMARY OF THE INVENTION
It is therefore the object of the present invention to provide a stage apparatus where even if a control system for a planar motor constituting a drive source is simplified, inter-axial interference is suppressed and highly precise positioning is possible.
It is a further object of the present invention to provide inspection apparatus capable of improving the precision of positioning a sample mounted on a table.
It is a still further object of the present invention to provide beam irradiation apparatus capable of improving the precision of positioning a sample mounted on a table.
The stage apparatus of the present invention comprises a base member, a table member provided at the base member and moving within a plane parallel to a guide plane, a first guide member for guiding the table member in a first direction and moving along the guide plane, a second guide member for guiding the first guide member in a second direction perpendicular with respect to the first direction, a non-contact bearing for providing guidance and support in such a manner that there is no contact between the base member, table member and second guide member, and the first guide member, a planar motor constituted by magnets provided at one of either the base member or the table member and electromagnets provided at the remaining one of either the base member or the table member, and movement control apparatus for controlling the planar motor, generating drive force in directions parallel to the guide plane, and moving the table member.
In this stage apparatus, the first guide member is provided with an opening penetrating to the guide plane so that the table member moves along the guide plane within the opening and is provided with levitation apparatus for causing the table member to levitate away fro
Jones Judson
Nikon Corporation
Ramirez Nestor
LandOfFree
Stage apparatus and inspection apparatus having stage apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Stage apparatus and inspection apparatus having stage apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stage apparatus and inspection apparatus having stage apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2954315