A method for calculating a spatial map associated with a component, the spatial map indicating spatial variations of thermal expansion parameters in the component, the method comprising: providing or determining a temperature distribution in the component as a function of time; calculating the spatial map associated with the component using the provided or determined temperature distribution in the component and optical measurements of a radiation beam that has interacted directly or indirectly with the component, the optical measurements being time synchronized with the provided or determined temperature distribution in the component.

A measurement apparatus including an illumination system configured to illuminate a target with light including light of a first wavelength and light of a second wavelength, a wavefront changing unit configured to change a wavefront aberration in light from the target, and a control unit configured to control the wavefront changing unit, wherein the wavefront changing unit includes a first region where the light of the first wavelength enters, and a second region where the light of the second wavelength enters, and the control unit controls the wavefront changing unit such that a first correction wavefront for correcting a first wavefront aberration in the light of the first wavelength is generated in the first region, and a second correction wavefront for correcting a second wavefront aberration in the light of the second wavelength is generated in the second region.

A transmissive diffraction grating for a phase-stepping measurement system for determining an aberration map for a projection system comprises an absorbing layer. The diffraction grating is for use with radiation having a first wavelength (for example (EUV radiation). The absorbing layer is provided with a two-dimensional array of through-apertures. The absorbing layer is formed from a material which has a refractive index for the radiation having the first wavelength in the range 0.% to 1.04.

Methods and systems for estimating values of process parameters based on measurements of structures fabricated on a product wafer are presented herein. Exemplary process parameters include lithography dosage and exposure and lithography scanner aberrations. A measurement model is employed to estimate process parameter values from measurements of structures fabricated on a wafer by a particular fabrication process. The measurement model includes process parameters and geometric parameters of structures under measurement. In some embodiments, a model based regression of both a process model and a metrology model is employed to arrive at estimates of at least one process parameter value based on measurements of a fabricated structure. In some embodiments, a trained measurement model is employed to directly estimate process parameter values based on measurements of structures. The measurement model is trained based on simulated measurement signals associated with measurements of shape profiles generated by different sets of process parameter values.

A projection exposure method and apparatus are disclosed for exposing a radiation-sensitive substrate with at least one image of a pattern of a mask under the control of an operating control system of a projection exposure apparatus, part of the pattern lying in an illumination region is imaged onto the image field on the substrate with the aid of a projection lens, wherein all rays of the projection radiation contributing to the image generation in the image field form a projection beam path.

An exposure apparatus arranged to project a radiation beam onto a target portion of a substrate, the exposure apparatus having: a first substrate holder configured to hold the substrate; a second substrate holder configured to hold the substrate; a sensor holder configured to hold a sensor and/or detector; a first measurement device having a first alignment system having an alignment sensor configured to measure positions of a substrate alignment mark on the substrate; a second measurement device having a second alignment system having a further alignment sensor configured to measure positions of the substrate alignment mark on the substrate; a first scale arranged on a lower surface of the first substrate holder; and a first encoder head arranged to cooperate with the first scale, the first encoder head located beneath the first alignment system and held by a stationary support.

Embodiments described herein relate to a dynamically controlled lens used in lithography tools. Multiple regions of the dynamic lens can be used to transmit a radiation beam for lithography process. By allowing multiple regions to transmit the radiation beam, the dynamically controlled lens can have an extended life cycle compared to conventional fixed lens. The dynamically controlled lens can be replaced or exchanged at a lower frequency, thus, improving efficiency of the lithography tools and reducing production cost.

A light intensity fluctuation-insensitive projection objective wave aberration detection device and a detection method thereof, comprising a light source and illumination system, an object plane marking plate, an object plane displacement table, a tested projection objective, an image plane marking plate, a two-dimensional photosensor, an image plane displacement table and a control processing unit; the object plane marking plate and the image plane marking plate are provided with grating marks for shear interference test and marks for light intensity test, the shear interferograms and the light intensity information are simultaneously received through the two-dimensional photosensor, the light intensity fluctuation error corresponding to each phase-shifting interferogram is corrected through the light intensity information, improving the detection precision, reducing the complexity and the cost of the system, and improving the detection speed.

An exposure apparatus that performs an exposure operation of exposing a substrate via a projection optical system is provided. The apparatus includes a temperature regulator configured to regulate a temperature distribution on an optical element of the projection optical system, and a controller configured to perform, in an exposure operation period in which the exposure operation is executed, a first process of controlling the temperature regulator so as to reduce a change of aberration of the projection optical system caused by execution of the exposure operation. In accordance with detection of a predetermined event before the exposure operation period, the controller performs, before performing the first process, a second process for reducing the aberration of the projection optical system using a method different from the first process.

An exposure method of performing an exposure operation of exposing a substrate via a projection optical system is provided. The method includes executing, in an exposure period in which the exposure operation is performed, aberration correction of the projection optical system to correct an aberration generated by performing the exposure operation, measuring, in a non-exposure period succeeding the exposure period, in which the exposure operation is not performed, an aberration of the projection optical system, and correcting the aberration of the projection optical system using a correction amount adjusted based on a result of the measurement so as to reduce a correction residual in the aberration correction of the projection optical system.