Patent ID: 7224428

Claim:
A lithographic apparatus, comprising: a substrate holder configured to hold a substrate; an illuminator configured to condition a beam of radiation; a support structure configured to support a patterning device that imparts a desired pattern onto the beam of radiation, the support structure including a stage; a projection system that projects the patterned beam to a target portion of the substrate; and a controller configured to control a quantity representing an attribute of a movable part of the apparatus, the controller comprising: at least two integrators connected in series; an integrator output circuit configured to derive an output quantity of the series-connected integrators from a respective output quantity of at least one of the integrators of the series-connected integrators; an integrator saturator operatively coupled to the integrator output circuit, the integrator saturator having an operating area in which the output quantity is passed through and a saturation area in which the output quantity is limited; and a saturation controller configured to set the 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 an input quantity or the output quantity of at least one of the series-connected integrators has a value that is capable of bringing the integrator saturator from the saturation region to the operating area.