Abstract:
A lithographic apparatus including a support to support a patterning device, a substrate table to hold a substrate, and a projection system to project a radiation beam patterned by the patterning device onto a target portion of the substrate. A transparent layer is provided to protect the pattering device. The apparatus further includes a transparent layer deformation-determining device to determine a deformation profile of the transparent layer, the deformation profile of the transparent layer expressing a deformation of the transparent layer during a scanning movement of the lithographic apparatus, and a compensator device which is configured to control the projection system, the substrate table and/or the support in response to the deformation profile of the transparent layer to compensate for the deformation of the transparent layer during the scanning movement of the apparatus.
Abstract:
Disclosed is an apparatus and method for performing a measurement operation on a substrate in accordance with one or more substrate alignment models. The one or more substrate alignment models are selected from a plurality of candidate substrate alignment models. The apparatus, which may be a lithographic apparatus, includes an external interface which enables selection of the substrate alignment model(s) and/or alteration of the substrate alignment model(s) prior to the measurement operation.
Abstract:
A method including determining a position of a first pattern in each of a plurality of target portions on a substrate, based on a fitted mathematical model, wherein the first pattern includes at least one alignment mark, wherein the mathematical model is fitted to a plurality of alignment mark displacements (dx, dy) for the alignment marks in the target portions, and wherein the alignment mark displacements are a difference between a respective nominal position of the alignment mark and measured position of the alignment mark; and transferring a second pattern onto each of the target portions, using the determined position of the first pattern in each of the plurality of target portions, wherein the mathematical model includes polynomials Z1 and Z2: Z1=r2 cos(2θ) and Z2=r2 sin(2θ) in polar coordinates (r, θ) or Z1=x2−y2 and Z2=xy in Cartesian coordinates (x, y).