Abstract: Embodiments of the present invention provide methods for optimizing a lithographic projection apparatus including optimizing projection optics therein. The current embodiments include several flows including optimizing a source, a mask, and the projection optics and various sequential and iterative optimization steps combining any of the projection optics, mask and source. The projection optics is sometimes broadly referred to as “lens”, and therefore the optimization process may be termed source mask lens optimization (SMLO). SMLO may be desirable over existing source mask optimization process (SMO) or other optimization processes that do not include projection optics optimization, partially because including the projection optics in the optimization may lead to a larger process window by introducing a plurality of adjustable characteristics of the projection optics.

Abstract: Systems and methods for conducting charged particle beam modulation are disclosed. According to certain embodiments, a charged particle beam apparatus generates a plurality of charged particle beams. A modulator may be configured to receive the plurality of charged particle beams and generate a plurality of modulated charged particle beams. A detector may be configured to receive the plurality of modulated charged particle beams.

Abstract: In a method of controlling a lithographic apparatus, historical performance measurements are used to calculate a process model relating to a lithographic process. Current positions of a plurality of alignment marks provided on a current substrate are measured and used to calculate a substrate model relating to a current substrate. Additionally, historical position measurements obtained at the time of processing the prior substrates are used with the historical performance measurements to calculate a model mapping. The model mapping is applied to modify the substrate model. The lithographic apparatus is controlled using the process model and the modified substrate model together. Overlay performance is improved by avoiding over- or under-correction of correlated components of the process model and the substrate model. The model mapping may be a subspace mapping, and dimensionality of the model mapping may be reduced, before it is used.

Abstract: Disclosed is a method and associated apparatus for measuring a characteristic of interest relating to a structure on a substrate. The method comprises calculating a value for the characteristic of interest directly from the effect of the characteristic of interest on at least the phase of illuminating radiation when scattered by the structure, subsequent to illuminating said structure with said illuminating radiation.

Abstract: A substrate table configured to support a substrate for exposure in an immersion lithographic apparatus, the substrate table including: a support body having a support surface configured to support the substrate; and a cover ring fixed relative to the support body and configured to surround, in plan view, the substrate supported on the support surface, wherein the cover ring has an upper surface and at least a portion of the upper surface is configured so as to alter the stability of a meniscus of immersion liquid when moving along the upper surface towards the substrate.

Abstract: An interferometer system, including a heterodyne interferometer and a processing system. The heterodyne interferometer is arranged to provide a reference signal and a measurement signal. The reference signal has a reference phase. The measurement signal has a measurement phase and an amplitude. The processing system is arranged to determine a cyclic error of the heterodyne interferometer based on the reference phase, the measurement phase and the amplitude.

Abstract: A debris mitigation system for use in a radiation source. The debris mitigation system comprises a contamination trap. The contamination trap comprises a debris receiving surface arranged to receive liquid metal fuel debris emitted from a plasma formation region of the radiation source. The debris receiving surface is constructed from a material that reacts with the liquid metal fuel debris to form an intermetallic layer on the debris receiving surface.

Abstract: In a lithographic projection apparatus, a structure surrounds a space between the projection system and a substrate table of the lithographic projection apparatus. A gas seal is formed between said structure and the surface of said substrate to contain liquid in the space.

Abstract: A hollow-core fiber (100) of non-bandgap type comprises a hollow core region (10) axially extending along the hollow-core fiber (100) and having a smallest transverse core dimension (D), wherein the core region (10) is adapted for guiding a transverse fundamental core mode and transverse higher order core modes, and an inner cladding region (20) comprising an arrangement of anti-resonant elements (AREs) (21, 21A, 21B) surrounding the core region (10) along the hollow-core fiber (100), each having a smallest transverse ARE dimension (di) and being adapted for guiding transverse ARE modes, wherein the core region (10) and the AREs (21, 21A, 21B) are configured to provide phase matching of the higher order core modes and the ARE modes and the ARE dimension (di) and the core dimension (D) are selected such that a ratio of the ARE and core dimensions (di/D) is approximated to a quotient of zeros of Bessel functions of first kind (ulm,ARE/ulm,core), multiplied with a fitting factor in a range of 0.9 to 1.

Abstract: A method involving measuring a first metrology target designed for a first range of values of a process parameter; measuring a second metrology target designed for a second range of values of the same process parameter, the second range different than the first range and the second metrology target having a different physical design than the first metrology target; and deriving process window data from a value of the process parameter in the first range determined from the measuring of the first metrology target, and from a value of the process parameter in the second range determined from the measuring of the second metrology target.

Abstract: A method and apparatus for obtaining focus information relating to a lithographic process. The method includes illuminating a target, the target having alternating first and second structures, wherein the form of the second structures is focus dependent, while the form of the first structures does not have the same focus dependence as that of the second structures, and detecting radiation redirected by the target to obtain for that target an asymmetry measurement representing an overall asymmetry of the target, wherein the asymmetry measurement is indicative of focus of the beam forming the target. An associated mask for forming such a target, and a substrate having such a target.

Abstract: A method to improve a lithographic process of imaging a portion of a design layout onto a substrate using a lithographic projection apparatus, the method including: computing a multi-variable cost function, the multi-variable cost function being a function of a stochastic variation of a characteristic of an aerial image or a resist image, or a function of a variable that is a function of the stochastic variation or that affects the stochastic variation, the stochastic variation being a function of a plurality of design variables that represent characteristics of the lithographic process; and reconfiguring one or more of the characteristics of the lithographic process by adjusting one or more of the design variables until a certain termination condition is satisfied.

Abstract: A lithographic apparatus comprises a projection system which is configured to project a patterned radiation beam to form an exposure area on a substrate held on a substrate table. The lithographic apparatus further comprises a heating apparatus comprises one or more radiation sources configured to provide additional radiation beams which illuminate and heat part of the substrate during the exposure.

Abstract: A topography measurement system comprising a radiation source configured to generate a radiation beam, a spatially coded grating configured to pattern the radiation beam and thereby provide a spatially coded radiation beam, optics configured to form an image of the spatially coded grating at a target location on a substrate, detection optics configured to receive radiation reflected from the target location of the substrate and form an image of the grating image at a second grating, and a detector configured to receive radiation transmitted through the second grating and produce an output signal.

Abstract: A radiation source comprising a fuel source configured to deliver fuel to a location from which the fuel emits EUV radiation. The radiation source further comprises an immobile fuel debris receiving surface provided with a plurality of grooves. The grooves have orientations which are arranged to direct the flow of liquid fuel under the influence of gravity in one or more desired directions.

Abstract: Measurement system comprising a radiation source configured to generate a measurement radiation beam, a polarizer and a grating to receive the measurement radiation beam and provide a polarized measurement radiation beam patterned by the grating, optics to form an image of the grating at a target location on a substrate. The image comprises a first part having a first polarization and a second part having a second polarization, detection optics to receive radiation from the target location of the substrate and form an image of the grating image at a second grating, and a detector to receive radiation transmitted through the second grating and produce a two output signal indicative of the intensity of the transmitted radiation for the first and second parts of the grating image respectively. Topography of the substrate can be determined from the signals.

Abstract: Disclosed is a method of measuring a parameter of interest relating to a structure on a substrate, and associated metrology apparatus. The method comprises determining a correction to compensate for the effect of a measurement condition on a measurement signal from a plurality of measurement signals, wherein each of said measurement signals results from a different measurement of the structure performed under a different variation of said measurement condition. The correction is then used in a reconstruction of a mathematical model of said structure to suppress an influence of variations of said measurement condition on the reconstruction.

Abstract: A multi-beam apparatus for observing a sample with high resolution and high throughput is proposed. In the apparatus, a source-conversion unit forms plural and parallel images of one single electron source by deflecting plural beamlets of a parallel primary-electron beam therefrom, and one objective lens focuses the plural deflected beamlets onto a sample surface and forms plural probe spots thereon. A movable condenser lens is used to collimate the primary-electron beam and vary the currents of the plural probe spots, a pre-beamlet-forming means weakens the Coulomb effect of the primary-electron beam, and the source-conversion unit minimizes the sizes of the plural probe spots by minimizing and compensating the off-axis aberrations of the objective lens and condenser lens.

Abstract: A patterning apparatus for a lithographic apparatus, the patterning apparatus including a patterning device support structure configured to support a patterning device having a planar surface; a patterning device conditioning system including a first gas outlet configured to provide a first gas flow over the planar surface in use and a second gas outlet configured to provide a second gas flow over the planar surface in use, wherein the first gas outlet and the second gas outlet are arranged at different distances perpendicular to the planar surface; and a control system configured to independently control a first momentum of gas exiting the first gas outlet and a second momentum of gas exiting the second gas outlet or to independently vary the first gas flow and/or the second gas flow over the planar surface of the patterning device.

Abstract: A method including obtaining a measurement result from a target on a substrate, by using a substrate measurement recipe; determining, by a hardware computer system, a parameter from the measurement result, wherein the parameter characterizes dependence of the measurement result on an optical path length of the target for incident radiation used in the substrate measurement recipe and the determining the parameter includes determining dependence of the measurement result on a relative change of wavelength of the incident radiation; and if the parameter is not within a specified range, adjusting the substrate measurement recipe.