Abstract:
A positioning system for positioning an object in a lithographic apparatus, including: a first and second object tables moveable in an operating area; a first position measurement system to provide an incremental position measurement of the second object table relative to a reference when in the operating area, wherein the first position measurement system is configured to provide an absolute position measurement of the first object table relative to the reference; a second position measurement system to provide an absolute position measurement of the first object table relative to the second object table, and wherein the first position measurement system is further configured to provide an absolute position measurement of the second object table relative to the reference based on the absolute position measurement of the first object table relative to the reference and on the absolute position measurement of the first object table relative to the second object table.
Abstract:
A positioning system for positioning an object in a lithographic apparatus, including: a first and second object tables moveable in an operating area; a first position measurement system to provide an incremental position measurement of the second object table relative to a reference when in the operating area, wherein the first position measurement system is configured to provide an absolute position measurement of the first object table relative to the reference; a second position measurement system to provide an absolute position measurement of the first object table relative to the second object table, and wherein the first position measurement system is further configured to provide an absolute position measurement of the second object table relative to the reference based on the absolute position measurement of the first object table relative to the reference and on the absolute position measurement of the first object table relative to the second object table.
Abstract:
The invention provides a wavelength tracking system comprising a wavelength tracking unit and an interferometer system. The wavelength tracking unit has reflection surfaces at stabile positions providing a first reflection path with a first path length and a second reflection path with a second path length. The first path length is substantially larger than the second path length. The interferometer system comprises: a beam splitter to split a light beam in a first measurement beam and a second measurement beam; at least one optic element to guide the first measurement beam, at least partially, along the first reflection path and the second measurement beam, at least partially, along the second reflection path; a first light sensor arranged at an end of the first reflection path to receive the first measurement beam and to provide a first sensor signal on the basis of the first measurement beam; a second light sensor arranged at an end of the second reflection path to receive the second measurement beam and to provide a second sensor signal on the basis of the second measurement beam; and a processing unit to determine a wavelength or change in wavelength on the basis of the first sensor signal and the second sensor signal.
Abstract:
A metrology tool for determining a parameter of interest of a structure fabricated on a substrate, the metrology tool comprising: an illumination optical system for illuminating the structure with illumination radiation under a non-zero angle of incidence; a detection optical system comprising a detection optical sensor and at least one lens for capturing a portion of illumination radiation scattered by the structure and transmitting the captured radiation towards the detection optical sensor, wherein the illumination optical system and the detection optical system do not share an optical element.
Abstract:
A measurement system configured to measure a position dependent signal of an object table, the measurement system including at least one sensor mountable on the object table and a sensor target object mountable on a substantially stationary frame, and a mounting device configured to mount the sensor target object on the substantially stationary frame, wherein the measurement system further includes a compensator configured to compensate movements and/or deformations of the sensor target object with respect to the substantially stationary frame. The compensator may include a passive or an active damper and/or a feedback position controller. In an alternative embodiment, the compensator includes a gripping device which fixes the position of the sensor target object during a high accuracy movement of the movable object.
Abstract:
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.
Abstract:
A method for calibrating an encoder scale having an array of marks in a first direction, includes moving the encoder scale in the first direction relative to a first encoder-type sensor, a second encoder-type sensor and a third encoder-type sensor, wherein the first encoder-type sensor and the second encoder-type sensor are fixedly spaced in the first direction at a first distance relative to each other, wherein the second encoder-type sensor and the third encoder-type sensor are fixedly spaced in the first direction at a second distance relative to each other.
Abstract:
A lithographic apparatus including a moveable object (WT) and a displacement measuring system arranged to determine a position quantity of the moveable object. The displacement measuring system includes an encoder (BC) and a grid structure. One of the encoder and the grid structure is connected to the moveable object. The grid structure includes a high precision grid portion (HG) and a low precision grid portion (LG). The encoder is arranged to cooperate with the high precision grid portion to determine the position quantity relative to the grid structure with a high precision. The encoder is arranged to cooperate with the low precision grid portion to determine the position quantity relative to the grid structure with a low precision.
Abstract:
An interferometer system, including a heterodyne interferometer and a processing system. The heterodyne interferometer is arranged to provide a reference signal and a measurement signal. The reference signal has a reference phase. The measurement signal has a measurement phase and an amplitude. The processing system is arranged to determine a cyclic error of the heterodyne interferometer based on the reference phase, the measurement phase and the amplitude.
Abstract:
A lithographic apparatus includes an optical sensor, a movable body, a support, a deflector system, a first drive system and a second drive system. The movable body is moveable relative to the sensor. The support is for holding the sensor. The first drive system is arranged to move the movable body relative to the sensor. The second drive system is arranged to move the first drive system relative to the sensor. The second drive system is arranged to move the deflector system relative to the sensor. A disturbance is induced by a movement of the movable body. The deflector system is arranged to create a deflecting area for reflecting the disturbance away from the support.