Abstract:
A measurement system for a lithographic apparatus comprises a sub-frame (100) compliantly mounted on a reference frame (RF). A measurement device, e.g. an alignment sensor (AS), is mounted on the sub-frame. The soft mounting (101) of the sub-frame isolates the alignment sensor from high-frequency disturbances, e.g. acoustic noise, by acting as a low-pass filter with a cut-off frequency, e.g. in the range of from 100 to 200 Hz.
Abstract:
The invention relates to a vibration isolator (VI), comprising: a base (10); a coupling element (20) to be coupled to a vibration sensitive object; a decoupling mass (30); a first vibration isolator part (31) arranged between the base (10) and the decoupling mass (30); and a second vibration isolator part (40) arranged between the decoupling mass (30) and the coupling element (20), and wherein at least one of the first and second vibration isolator part comprises a pneumatic isolator.
Abstract:
A lithographic apparatus is described, the lithographic apparatus comprising: - an illumination system (IL) configured to condition a radiation beam; - a support (SA2) constructed to support a patterning device (MA), the patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam (PR); - a projection system (PS) configured to project the patterned radiation beam onto a target portion of a substrate (W), - a stage assembly (SA) comprising: - a substrate table (WT) constructed to hold the substrate; and - a positioning device configured to displace the substrate table relative to the projection system; - a base frame onto which stage assembly and the projection system are mounted; - the base frame comprising a first portion (SABF) configured to support the stage assembly and a second portion (BF2) configured to support the projection system, the first portion and the second portion being connected to each other via a compliant portion (DC) of the base frame.
Abstract:
A lithographic apparatus comprising a moveable object (WT) and a displacement measuring system arranged to determine a position quantity of the moveable object. The displacement measuring system comprises an encoder (EC) and a grid structure. One of the encoder and the grid structure is connected to the moveable object. The grid structure comprises 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.