The invention provides a method for thermo-mechanical control of a heat sensitive element (Ml) subject to a heat load, comprising: -providing a non-linear thermo-mechanical model of the heat sensitive element describing a dynamical relationship between characteristics of the heat load and deformation of the heat sensitive element; -calculating a control signal on the basis of an optimization calculation of the non-linear model, -providing an actuation signal to a heater (HE), wherein the actuation signal is at least partially based on the control signal, -heating the heat sensitive element by the heater on the basis of the actuation signal.

A lithographic apparatus comprises a projection system comprising position sensors to measure a position of optical elements of the projection system. The positions sensors are referenced to a sensor frame. Damping actuators damp vibrations of the sensor frame. A control device drives the actuators and is configured to derive sensor frame damping force signals from at least one of the acceleration signals and the sensor frame position signals, derive an estimated line of sight error from the position signals, determine actuator drive signals from the sensor frame damping force signals and the estimated line of sight error, drive the actuators using the actuator drive signals to dampen the sensor frame and to at least partly compensate the estimated line of sight error.

A method of manufacturing a semiconductor device by using an exposure apparatus having a reticle stage and a projection optical system includes a first period in which substrates are exposed by using a first reticle arranged on the reticle stage, a second period in which substrates are exposed by using a second reticle arranged on the reticle stage, and a third period which is between the first and second periods. The method includes changing, in at least part of the third period, the first reticle arranged on the reticle stage to the second reticle, and performing control, in the first and second periods, to adjust temperature distribution of an optical element of the projection optical system so as to reduce change in aberration of the projection optical system. The third period is shorter than the first period.

An exposure apparatus that exposes a substrate to light by using an original in which a pattern is formed includes an illumination optical system arranged to guide illumination light to the original, the illumination light including first illumination light with a first wavelength and second illumination light with a second wavelength different from the first wavelength, and a projection optical system arranged to form a pattern image of the original by using the illumination light at a plurality of positions in an optical axis direction. The illumination optical system is configured to adjust a position deviation in a direction perpendicular to the optical axis direction between a pattern image formed by the first illumination light and a pattern image formed by the second illumination light by changing an incident angle of the illumination light entering the original.

A microlithographic projection exposure apparatus comprises a projection lens for projecting structures of a mask into a substrate plane via exposure radiation. At least one optical element of the projection lens is provided with a manipulator configured for the targeted input of thermal energy into the optical element, without one of further optical elements of the projection lens being significantly heated in the process. The projection exposure apparatus furthermore comprises a control device configured for controlling the exposure radiation and for controlling the manipulator so that an effect on an optical property of the projection lens that is caused by a decrease in a thermal energy input into the projection lens due to an exposure pause is at least partly compensated for by the energy input via the manipulator. Furthermore, the disclosure relates to a corresponding method for controlling a microlithographic projection exposure apparatus.

A multi-channel device and method for measuring the distortion and magnification of objective lens. The multi-channel device for measuring the distortion and magnification of objective lens comprises an illumination system, a reticle stage, a test reticle, a projection objective lens, a wafer stage and a multi-channel image plane sensor, wherein the multi-channel image plane sensor simultaneously measures the image placement shifts between actual image points and nominal image points after a plurality of object plane test marks are imaged by the projection objective lens, and calculates the distortion and magnification errors of the objective lens by fitting, which shortens the measurement time, eliminates the influence of wafer stage errors on the measurement accuracy and improves the measurement accuracy.

A lithographic apparatus comprising a projection system comprising at least one optical component and configured to project a pattern onto a substrate. The lithographic apparatus further comprises a control system arranged to reduce the effects of heating and/or cooling of an optical component in a lithographic process. The control system is configured at least: to select at least one of a plurality of mode shapes to represent a relationship between at least one input in the lithographic process and an aberration resulting from the input and to generate and apply a correction to the lithographic apparatus based on the mode shape.

A method at tuning a lithographic process for a particular patterning device. The method includes: obtaining wavefront data relating to an objective lens of a lithographic apparatus, the wavefront data measured subsequent to an exposure of a pattern on a substrate using the particular patterning device; determining a pattern specific wavefront contribution from the wavefront data and a wavefront reference, the pattern specific wavefront contribution relating to the patterning device; and tuning the lithographic process for the particular patterning device using the pattern specific wavefront contribution.

A method for determining process window limiting patterns based on aberration sensitivity associated with a patterning apparatus. The method includes obtaining (i) a first set of kernels and a second set of kernels associated with an aberration wavefront of the patterning apparatus and (ii) a design layout to be printed on a substrate via the patterning apparatus; and determining, via a process simulation using the design layout, the first set of kernels, and the second set of kernels, an aberration sensitivity map associated with the aberration wavefront, the aberration sensitivity map indicating how sensitive one or more portions of the design layout are to an individual aberrations and an interaction between different aberrations; determining, based on the aberration sensitivity map, the process window limiting pattern associated with the design layout having relatively high sensitivity compared to other portions of the design layout.

An optical measuring system is used to reproduce a target wavefront of an imaging optical production system when an object is illuminated with illumination light. The optical measuring system comprises an object holder displaceable by actuator means and at least one optical component displaceable by actuator means. Within the scope of the target wavefront reproduction, a starting actuator position set (X.sub.0), in which each actuator is assigned a starting actuator position, is initially specified. An expected design wavefront (W.sub.D) which approximates the target wavefront and which the optical measuring system produces as a set wavefront is determined. A coarse measurement of a starting wavefront (W.sub.0) which the optical measuring system produces as actual wavefront after actually setting the starting actuator position set (X.sub.0) is carried out. Then, the object holder is adjusted by actuator means until a coarse target wavefront (W.sub.1) is obtained for a coarse actuator position set (X.sub.1) in the case of a minimum wavefront deviation between the actual wavefront and the design wavefront (W.sub.D). Said coarse target wavefront is then subjected to a fine measurement and the at least one optical component is displaced until a fine target wavefront (W.sub.2) is obtained for a fine actuator position set (X.sub.2) in the case of a minimum deviation between the actual wavefront setting-in in that case and the design wavefront (W.sub.D). This reproduction method allows wavefront deviations of the optical measuring system generated by way of targeted misalignment to provide a good approximation of corresponding deviations of the optical production system.