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US 12,468,115 B2Granted
Filter assembly, in particular for a control loop for controlling the position of at least one element
AssigneeCarl Zeiss SMT GmbH
InventorThomas Gorius
Life of this patent
Estimating the term…
Abstract
A filter assembly, for example for a control loop for controlling the position of at least one element, comprises first and second filters. The first filter suppresses an undesired component in a signal to be filtered. The first filter produces a first signal delay in a first frequency range. The second filter produces a second signal delay in the first frequency range. The second signal delay at least partly compensates the first signal delay.
Claims22
A control loop configured to control a position of an optical element of a microlithographic projection exposure apparatus, the control loop comprising:
- a controller configured to control a force exerted on the optical element by an actuator of the microlithographic projection exposure apparatus based on a reference signal;
- and
- a filter arrangement, comprising:
- a first filter configured to:
- i) suppress an unwanted component in the reference signal;
- and ii) cause a first signal delay in a first frequency range of the reference signal;
- and
- a second filter configured to cause a second signal delay in the first frequency range of the reference signal,
- wherein the second signal delay at least partially compensates the first signal delay.
6 more elements
An apparatus, comprising:
- an optical element;
- an actuator configured to exert a force on the optical element;
- a controller configured to control a position of the optical element by controlling a force exerted on the optical element by the actuator based on a reference signal;
- and
- a filter arrangement, comprising:
- a first filter configured to:
- i) suppress an unwanted component in the reference signal;
- and ii) cause a first signal delay in a first frequency range of the reference signal;
- and
- a second filter configured to cause a second signal delay in the first frequency range of the reference signal,
- wherein the apparatus is a microlithographic projection exposure apparatus.
8 more elements
Dependencies are inferred from the claim text.