Abstract: In a lithographic apparatus, a feedforward transfer function of a control system is determined by: a) iteratively learning a feedforward output signal of the control system by iterative learning control for a given setpoint signal; b) determining a relation between the learned feedforward output signal and the setpoint signal; and c) applying the relation as the feedforward transfer function of the control system. A learned feedforward, which has been learned for one or more specific setpoint signals only, can be adapted to provide a setpoint signal dependent feedforward output signal. The learned feedforward can be made more robust against setpoint variations.

Abstract: A lithographic apparatus includes a projection system to project a patterned beam of radiation onto a substrate, which is held on a substrate support and a drive system to move the substrate support along a trajectory. In the drive system, set-point data, including set-point coordinates, are generated for moving the substrate support relative to the projection system in a first and second directions. The set-point coordinates of the first and second directions are transformed into set-point coordinates of third and fourth directions. Motion data, including motion coordinates, are generated for moving the substrate support relative to the projection system in the third and fourth directions, limiting the velocity in the third and fourth directions to a maximum velocity. The motion coordinates of the third and fourth directions are transformed into motion coordinates of the first and second directions for driving the first and second drive motors.

Abstract: A lithographic apparatus includes a first control system to control a first physical quantity in the lithographic apparatus. A parameter in the first control system is dependent on a value of a further physical quantity in the lithographic apparatus. The parameter may be included in a feedforward path. An input of the feedforward path may be connected to a second control system, the second control system to control a second physical quantity in the lithographic apparatus. The feedforward path may provide a feedforward signal to the first control system in dependency on a signal in the second control system. The further physical quantity may include the second physical quantity.

Abstract: A lithographic apparatus includes a projection system to project a patterned beam of radiation onto a substrate, which is held on a substrate support and a drive system to move the substrate support along a trajectory. In the drive system, set-point data, including set-point coordinates, are generated for moving the substrate support relative to the projection system in a first and second directions. The set-point coordinates of the first and second directions are transformed into set-point coordinates of third and fourth directions. Motion data, including motion coordinates, are generated for moving the substrate support relative to the projection system in the third and fourth directions, limiting the velocity in the third and fourth directions to a maximum velocity. The motion coordinates of the third and fourth directions are transformed into motion coordinates of the first and second directions for driving the first and second drive motors.

Abstract: In a lithographic apparatus, a feedforward transfer function of a control system, is determined by: a) iteratively learning a feedforward output signal of the control system by iterative learning control for a given setpoint signal; b) determining a relation between the learned feedforward output signal and the setpoint signal; and c) applying the relation as the feedforward transfer function of the control system. A learned feedforward, which has been learned for one or more specific setpoint signals only, can be adapted to provide a setpoint signal dependent feedforward output signal. The learned feedforward can be made more robust against setpoint variations.

Abstract: A lithographic apparatus for immersion lithography is described in which a compensation controller controls actuators to apply forces to the substrate equal in magnitude and opposite in direction to forces which are applied to the substrate by a liquid supply system which supplies liquid between the projection system and the substrate.

Abstract: A lithographic apparatus comprising a control system, such as a motion control system, is presented. The control system includes an actuator for moving a moveable part, a feed-forward path from a setpoint input of the control system to the actuator, a feed-back loop, a feed-forward transfer function of the feed-forward path having a feed-forward transfer function part which is an inverse of a part of the actuator transfer function having a stable inverse, the actuator transfer function including a part having a stable inverse and a remainder potentially having an unstable inverse. The setpoint path includes a setpoint delay function, and the feed-forward transfer function further includes a second feed-forward transfer function part. A difference in delay between the setpoint delay function and the second feed-forward transfer function part is equal to a delay of the potentially unstable remainder of the actuator transfer function.

Abstract: A lithographic apparatus is presented that includes a controller having a series connection of at least two integrators and an integrator output circuit for deriving an output quantity of the series connection of integrators. The controller also includes an integrator saturator that is operatively coupled to the integrator output circuit and having an operating area for passing through the output quantity and a saturation area for saturating the output quantity. A saturation control mechanism for controlling saturation sets an output quantity of at least one of the series-connected integrators to a neutral value, when the integrator saturator is in the saturation area, except when the output quantity of or an input quantity of at least one of the series-connected integrators has a value such that it would tend to bring the integrator saturator from the saturation area to the operating area.

Abstract: A lithographic apparatus includes an illumination system configured to provide a beam of radiation, a first support structure configured to support a patterning device, a second support that includes a substrate holder for holding a substrate, a projection system configured to project the patterned beam of radiation onto the substrate, and a servo unit configured to position the substrate holder. The apparatus further includes a sensor unit configured to determine a distance of at least one location point on the surface of the substrate relative to a reference plane, a memory unit configured to store surface information of the substrate based on respective distances of corresponding location points on the substrate surface, and a calculating unit configured to determine a feed-forward set-point signal based on the stored surface information, such that the feed-forward set-point signal is forwardly fed to the servo unit in order to position the substrate holder.

Abstract: In a lithographic projection apparatus and a device manufacturing method, a movable part is controlled to produce a motion, an absolute value of at least one of a fourth and a higher derivative to time of the position of the motion being limited to less than a maximal value. Specifying at least one of a fourth and a higher derivative to time of the position may help to improve settling behavior to obtain more accurate positioning.