A lithographic apparatus and associated method of controlling a lithographic process. The lithographic apparatus has a controller configured to define a control grid associated with positioning of a substrate within the lithographic apparatus. The control grid is based on a device layout, associated with a patterning device, defining a device pattern which is to be, and/or has been, applied to the substrate in a lithographic process.

A method of unloading an object from a support table, the object clamped to the support table during an exposure process by: applying a first pressure to a central region of the support table under a central portion of the object; and applying a second pressure to a peripheral region of the support table under a peripheral portion of the object, wherein during clamping the first pressure and the second pressure are controlled such that liquid is retained between the object and a seal member that is positioned radially between the central region and the peripheral region at an upper surface of the support table and protrudes towards the object, the method including: increasing the first pressure towards ambient pressure; removing at least some of the liquid retained between the object and the seal member by decreasing the second pressure; and increasing the second pressure towards the ambient pressure.

A linear motor with high heat recovery efficiency that inhibits the rise in surface temperature is offered. The linear motor is disposed in a surrounding member (142) and facing a flow passage (142a) of a liquid for regulating temperature, and is provided with a coil unit (141) having at least a part thereof in contact with the liquid. The coil unit (141) is provided with a coil body (144), a mold layer (143) that covers the coil body and holds it in specific form, and a liquid protection layer (150) that covers the mold layer (143) and has liquid protection properties.

An exposure apparatus can mitigate the impact of fluctuations in the refractive index of ambient gas, and improve, for example, stage positioning accuracy. An exposure apparatus radiates an exposure illumination light to a wafer on a wafer stage through a projection optical system, and forms a prescribed pattern on the wafer, and comprises: a scale, which is provided to the wafer stage; a plurality of X heads, which detect information related to the position of the scale; a measurement frame that integrally supports the plurality of X heads and has a coefficient of linear thermal expansion that is smaller than that of the main body of the wafer stage (portions excepting a plate wherein the scale is formed); and a control apparatus that derives information related to the displacement of the wafer stage based on the detection results of the plurality of X heads.

Provided is a stage apparatus that includes a first movable unit; a linear motor that includes a stator coil array arranged over a stroke range in a predetermined direction of the first movable unit and a mover magnet fixed to the first movable unit; a second movable unit that is arranged to face the first movable unit via a space and relatively moves with respect to the first movable unit in the predetermined direction; and a switch unit that forms a closed circuit including coils in the stator coil array and a resistance during operation of a dynamic brake, wherein the resistance value of a first coil located at a center region of the stroke range in the stator coil array is larger than that of a second coil located toward an end side of the stroke range rather than the center region in the stator coil array.

A driving apparatus is disclosed which has a movable part, a measuring device measuring a position of the movable part, two actuators respectively generating two thrusts which have a common axis of action thereof with respect to the movable part, and a controller that controls the position by the two actuators based on output of the measuring device. The controller obtains information of at least one of a thrust constant of one of the two actuators, a thrust constant of the other of the actuators, and rigidity of a member which supports the movable part with respect to the axis of action, based on a relationship between disturbance force estimated from thrust commands for the two actuators and an output of the measuring device in a case where the one actuator generates a thrust and the other actuator controls the position, and a thrust command for the one actuator.

According to measurement results of an encoder system, a stage driving system that is a magnetic levitation type planar motor is controlled to drive and control a wafer stage, and in the case where an abnormality of the driving and control of the wafer stage has been detected, the stage driving system is controlled to apply a thrust in a vertical direction to the wafer stage. With this operation, the pitching of the wafer stage can be avoided, which makes it possible to prevent damage of the wafer stage and structures placed immediately above the stage upper surface.

An object table has a lifting mechanism to displace an object from a support surface. The lifting mechanism includes one or more elongated rods extending in a direction substantially perpendicular to the support surface to support the object at a distance from the support surface, the one or more elongated rods being displaceable between positions below the support surface and protruding from the support surface. The mechanism further includes a locking mechanism configured to limit a rotation about a longitudinal axis of the one or more elongated rods. The locking mechanism includes an elastic element that is mechanically connected to both a housing of the lifting mechanism and the one or more elongated rods, the elastic element configured to have a comparatively low stiffness in the support direction and a comparatively high stiffness in a rotational direction about the longitudinal axis.

A lithographic apparatus with a cover plate formed separately from a substrate table and means for stabilizing a temperature of the substrate table by controlling the temperature of the cover plate is disclosed. A lithographic apparatus with thermal insulation provided between a cover plate and a substrate table so that the cover plate acts as a thermal shield for the substrate table is disclosed. A lithographic apparatus comprising means to determine a substrate table distortion and improve position control of a substrate by reference to the substrate table distortion is disclosed.

A stage system includes a movable stage, and an encoder for measuring a position of the stage, wherein the encoder includes an emitter for emitting an encoder beam, a grating for interacting with the encoder beam, and a detector for detecting the encoder beam having interacted with the grating, the encoder beam in use propagating along an optical path; a purging cap at least partly enclosing the optical path; and a purging medium supply device for supplying a purging medium into the purging cap.