A substrate holder, for a lithographic apparatus, having a main body, a plurality of support elements to support a substrate and a seal unit. The seal unit may include a first seal positioned outward of and surrounding the plurality of support elements. A position of a substrate contact region of an upper surface of the first seal may be arranged at a distance from the plurality of support elements sufficient enough such that during the loading/unloading of the substrate, a force applied to the first seal by the substrate is greater than a force applied to the plurality of support elements by the substrate. A profile of the contact region, in a cross section through the seal, may have a shape which is configured such that during the loading/unloading of the substrate, the substrate contacts the seal via at least two different points of the profile.

A lithographic apparatus .[.comprising.]. .Iadd.includes .Iaddend.an object table .[.which carries an object.].. The lithographic apparatus may further .[.comprise at least one.]. .Iadd.include a .Iaddend.sensor .[.as part of a measurement system.]. to measure a characteristic of the object table, the environment surrounding the lithographic apparatus or another component of the lithographic apparatus. The measured characteristic may be used to estimate .[.the.]. .Iadd.a .Iaddend.deformation of .[.the.]. .Iadd.an .Iaddend.object due to .Iadd.a .Iaddend.varying .[.loads.]. .Iadd.load .Iaddend.during operation of the lithographic apparatus, for example .Iadd.a .Iaddend.varying .[.loads.]. .Iadd.load .Iaddend.induced by a two-phase flow in a channel formed .[.within.]. .Iadd.of .Iaddend.the object table. .[.Additionally, or alternatively, the.]. .Iadd.The .Iaddend.lithographic apparatus .[.comprises.]. .Iadd.may include .Iaddend.a predictor to estimate the deformation of the object based on a model. The positioning of the object table carrying the object can be controlled based on the estimated deformation. The positioning of a projection beam, used to .Iadd.provide a .Iaddend.pattern .[.a substrate.]., can be controlled relative to the object, to alter the position of the pattern and/or the projection beam on the substrate, based on the estimated deformation.

The invention provides an object positioner comprising:—an object support having an object support surface which is configured to engage at least a part of an object, said object support surface having a support surface temperature,—a thermal device, which thermal device is configured to provide at least a part of the object with a first object temperature, which first object temperature differs from the support surface temperature by a first predetermined temperature difference.

A method of fabricating a substrate table includes supporting a table base and disposing a coating on a surface of the table base. The surface of the table base is substantially flat. The coating has a non-uniform thickness. The coating exerts a stress on the table so as to bend the table base. The non-uniform thickness causes a surface of the coating to become substantially flat after the bending.

Some implementations described herein provide an exposure tool. The exposure tool includes a reticle deformation detector and one or more processors configured to obtain, via the reticle deformation detector, reticle deformation information associated with a reticle during a scanning process for scanning multiple fields of a wafer. The one or more processors determine, based on the reticle deformation information, a deformation of the reticle at multiple times during the scanning process, and perform, based on the deformation of the reticle at the multiple times, one or more adjustments of one or more components of the exposure tool during the scanning process.

An exposure method includes acquiring first height information through detection of a height of an upper surface of a substrate subjected to exposure; acquiring first position information through detection of a relative position between the substrate and a first mask having a first pattern to be transferred on the substrate; converting the first height information to second position information; acquiring second height information through detection of a height of the upper surface of the substrate; acquiring third position information through detection of a relative position between the substrate and a second mask having a second pattern to be transferred on the substrate; converting the second height information to fourth position information; calculating differential position information, based on difference between the second position information and the fourth position information; and aligning the second mask and the substrate, based on the third position information and the differential position information.

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 method including: generating a first force to attract a substrate holder to a support surface, the holder including a body having opposing first and second body surfaces, first burls at the first body surface, wherein each first burl has a distal end to support a substrate, and second burls at the second body surface to support the substrate holder on the support surface through contact with distal ends of the second burls; generating a second force to attract the substrate to the substrate holder; and controlling the first force and/or second force in a release step to deform the body between the second burls such as to create a gap between the distal ends of a first subset of the plurality of first burls and the substrate and such that the substrate is supported on distal ends of a second subset of the plurality of first burls.

A method and control system for determining stress in a substrate. The method includes determining a measured position difference between a measured position of at least one first feature and a measured position of at least one second feature which have been applied on a substrate, and determining local stress in the substrate from the measured position difference.

The present invention provides a testing substrate (W) for estimating stress in production substrates due to a substrate support, said testing substrate having a support surface (SS) divided into predefined portions, wherein the predefined portions comprise at least one first portion (1) having a first coefficient of friction being substantially uniform across the at least one first portion, and at least one second portion (2) having a second coefficient of friction being substantially uniform across the at least one second portion, wherein the second coefficient of friction is different to the first coefficient of friction. The present invention also provides a method for estimating stress in a substrate due to a substrate support and a system for making such an estimation.