compensation force on the first frame during operation, which compensation force has a
mechanical moment about a reference point of the first frame having a value equal to a
value of a mechanical moment of a force of gravity acting on the object table about said
reference point and a direction which is opposed to a direction of the mechanical moment
of said force of gravity.
Van Engelen claim 13 depends on van Engelen claim 11. Those claims are as follows:
11. A lithographic device with a machine frame which, seen parallel to a vertical Z
direction, supports in that order a radiation source, a mask holder which is displaceable
perpendicularly to the Z-direction by means of a positioning device, a focusing system
with a main axis directed parallel to the Z-direction, and a substrate holder which is
displaceable perpendicularly to the Z-direction by means of a further positioning device,
the positioning device of the mask holder including an object table and a drive unit by
which the object table is displaceable over a guide parallel to at least an X-direction,
which guide is fastened to a first frame of the positioning device while a stationary part of
the drive unit is fastened to a second frame of the positioning device which is
dynamically isolated from the first frame, wherein the first frame of the positioning
device of the mask holder belongs to the machine frame of the lithographic device, while
the second frame of the positioning device of the mask holder belongs to a force frame of
the lithographic device which is dynamically isolated from the machine frame; and
wherein a reaction force exerted by the object table on the drive unit during operation and
arising from a driving force exerted by the drive unit on the object table is transmittable
exclusively into the second frame.
13. A lithographic device as claimed in claim 11, wherein the positioning devices of the
substrate holder and the mask holder have a joint force actuator system which is
controlled by an electric control unit and which exerts a compensation force on the
machine frame of the lithographic device during operation which has a mechanical
moment about a reference point of the machine frame of a value which is equal to a value
of a sum of a mechanical moment of a force of gravity acting on the substrate holder
about said reference point and a mechanical moment of a force of gravity acting on the
mask holder about said reference point, and a direction which is opposed to a direction of
said sum of mechanical moments.
Van Engelen claim 15 depends on van Engelen claim 2, which depends on claim 1. Van
Engelen claims 2 and 15 are as follows.
2. A positioning device as claimed in claim 1, wherein the object table is coupled to the
stationary part of the drive unit exclusively by a Lorentz force of a magnet system and an
electric coil system of the drive unit during operation.
15. A positioning device as claimed in claim 2, wherein the positioning device is provided
with a force actuator system controlled by an electric control unit and exerting a
compensation force on the first frame during operation, which compensation force has a
mechanical moment about a reference point of the first frame having a value equal to a
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Last modified: November 3, 2007