Abstract: A method for calibrating an encoder in a lithographic apparatus, the encoder including a sensor and a grating, the encoder configured to measure a position of a moveable support of the lithographic apparatus, the method including measuring a position of the moveable support using an interferometer; and calibrating the encoder based on the position of the moveable support measured by the interferometer.

Abstract: A lithographic apparatus includes a position controller configured to control a position of a patterning device in its planar direction by selectively pressing at least one of the side faces of the patterning device. The position controller includes a gas pressure supply and one or more outflow openings directed towards at least one side face of the patterning device so as to exert pressurized gas on this side face in order to control the position of the patterning device in its planar direction in a contactless manner.

Abstract: A method of determining an overlay error in which asymmetry of a first order of a diffraction pattern is modeled as being a weighted sum of harmonics. Both the first order harmonic and higher order harmonics are non-negligible and weights for both are calculated. The weights are calculated using three or more of sets of superimposed patterns using a least mean square method.

Abstract: An overlay error between two successive layers produced by a lithographic process on a substrate is determined by using the lithographic process to form at least one periodic structure of a same pitch on each of the layers. One or more overlaid pairs of the periodic structures are formed in parallel, but offset relative to each other. A spectrum, produced by directing a beam of radiation onto the one or more pairs of periodic structures is measured. One or more portions of the spectrum are determined in which the relationship between the offset between the one or more pairs of periodic structures and the resultant variation in measured intensity of the spectrum at the one or more portions is more linear than the relationship outside the one or more portions. The offset between the one or more pairs of periodic structures on the basis of intensity measurements of the spectrum in the one or more portions of the spectrum is determined and used to determine the overlay error.

Abstract: A lithographic apparatus and device manufacturing method makes use of a liquid confined in a reservoir between the projection system and the substrate. Bubbles forming in the liquid from dissolved atmospheric gases or from out-gassing from apparatus elements exposed to the liquid are detected and/or removed so that they do not interfere with exposure and lead to printing defects on the substrate. Detection may be carried out by measuring the frequency dependence of ultrasonic attenuation in the liquid and bubble removal may be implemented by degassing and pressurizing the liquid, isolating the liquid from the atmosphere, using liquids of low surface tension, providing a continuous flow of liquid through the imaging field, and/or phase shifting ultrasonic standing-wave node patterns.

Abstract: A patterned beam of radiation is projected onto a substrate. A reflective optical element is used to help form the radiation beam from radiation emitted from a plasma region of a plasma source. In the plasma source, a plasma current is generated in the plasma region. To reduce damage to the reflective optical element, a magnetic field is applied in the plasma region with at least a component directed along a direction of the plasma current. This axial magnetic field helps limit the collapse of the Z-pinch region of the plasma. By limiting the collapse, the number of fast ions emitted may be reduced.

Abstract: A substrate handling apparatus for handling a substrate is disclosed. The substrate handling apparatus includes a substrate feeding device to feed the substrate towards an exposure area, a substrate receiving device to receive the substrate from the exposure area, and a substrate stabilization device to maintain, at least in the exposure area, the substrate substantially flat at an exposure height and/or tilt, the substrate stabilization device configured for contactless stabilization of the flexible substrate.

Abstract: A lithographic apparatus includes an illuminator for receiving a beam of EUV radiation from a radiation source apparatus and for conditioning the beam to illuminate a target area of a patterning device, such as a reticle. The reticle forms a patterned radiation beam. A projection system transfers the pattern from said patterning device to a substrate by EUV lithography. Sensors are provided for detecting a residual asymmetry in the conditioned beam as the beam approaches the reticle, particularly in a non-scanning direction. A feedback control signal is generated to adjust a parameter of said radiation source in response to detected asymmetry. The feedback is based on a ratio of intensities measured by two sensors at opposite ends of an illumination slit, and adjusts the timing of laser pulses generating an EUV-emitting plasma.

Abstract: In an embodiment, there is disclosed an inspection method for detecting the presence of imprintable medium on an imprint lithography template. The method includes contacting the imprint lithography template with a marker, the marker being attachable to imprintable medium that may be on the imprint lithography template, the marker being configured to interact with incident radiation when attached to the imprintable medium, directing radiation at the imprint lithography template, and measuring radiation re-directed by the imprint lithography template to attempt to detect presence of a marker that has attached to the imprintable medium, from the interaction of the marker with the incident radiation, and thus detect the presence of imprintable medium to which the marker is attached.

Abstract: A fluid handling structure for a lithographic apparatus, the fluid handling structure having, at a boundary from a space configured to contain immersion fluid to a region external to the fluid handling structure: a meniscus pinning feature to resist passage of immersion fluid in a radially outward direction from the space; a plurality of gas supply openings in a linear array at least partly surrounding and radially outward of the meniscus pinning feature; and a gas recovery opening radially outward of the plurality of gas supply openings in a linear array.

Abstract: A method is described for alignment of a substrate during a double patterning process. A first resist layer containing at least one alignment mark is formed on the substrate. After the first resist layer is developed, a second resist layer is deposited over the first resist layer, leaving a planar top surface (i.e., without topography). By baking the second resist layer appropriately, a symmetric alignment mark is formed in the second resist layer with little or no offset error from the alignment mark in the first resist layer. The symmetry of the alignment mark formed in the second resist can be enhanced by appropriate adjustments of the respective thicknesses of the first and second resist layers, the coating process parameters, and the baking process parameters.

Abstract: A fluid handling structure for a lithographic apparatus, the fluid handling structure having, at a boundary from a space configured to contain immersion fluid to a region external to the fluid handling structure: a meniscus pinning feature to resist passage of immersion fluid in a radially outward direction from the space; and a plurality of gas supply openings in a linear array at least partly surrounding and radially outward of the one or more meniscus pinning features, wherein the plurality of gas supply openings in a linear array are of a similar or the same size.

Abstract: A lithographic apparatus includes a positioner configured to position a first part of the apparatus relative to a second part of the apparatus, the positioner including a motor having a motor position dependent motor constant defining a relation between a motor input and a motor output, and a control system to drive the motor, the control system including a set-point generator to provide a reference signal based on a desired position of the first part relative to the second part, and a controller to provide a drive signal to the motor based on the reference signal, wherein the controller includes a compensator which is configured to at least partially compensate the drive signal for the motor position dependent motor constant. The invention further relates to a positioner, a method to optimize the positioning system, and a method to derive a motor position dependent motor constant.

Abstract: A lithographic apparatus, includes a support structure configured to hold a patterning device, the patterning device configured to impart a beam of radiation with a pattern in its cross-section; a substrate table configured to hold a substrate; a projection system configured to project the patterned beam onto a target portion of the substrate; a liquid supply system configured to provide liquid to a space between the projection system and the substrate table; a sensor configured to measure an exposure parameter using a measuring beam projected through the liquid; and a correction system configured to determine an offset based on a change of a physical property impacting a measurement made using the measuring beam to at least partly correct the measured exposure parameter.

Abstract: The Hessian (second derivative) of the image log slope (ILS) can be quickly and accurately calculated without the need to use approximate methods from the gradient of the ILS with respect to mask transmission and source intensity. The Hessian has been traditionally calculated using a finite-difference approach. Calculating the Hessian through a finite-difference approach is slow and is an approximate method. The gradient of the ILS improves the speed of calculation of the Hessian, and thus accelerated SMO operation is realized. The results of ILS evaluation can be used in design for manufacturing (DFM) to suggest changes in the design rules to improve imaging. For a fixed illumination, this information can help remove forbidden pitches and help select design rules for 1-D and 2-D patterns on a mask design layout.

Abstract: A lithographic apparatus having a component that moves in a first direction, the component including a passive gas flow system. The passive gas flow system has a gas inlet to drive gas into the passive gas flow system when the component moves in the first direction and a gas outlet, connected to the gas inlet by a gas conduit, to direct the gas that is driven into the passive gas flow system in a certain direction.

Abstract: A method of measuring a phase difference between two regions in an aberration function: Reference structures are produced on a substrate using illumination that minimizes effects of phase aberration. A grating is produced on the substrate using a phase-shift grating reticle to produce, in the exit pupil, a pair of diffracted non-zero orders, while forbidding other diffracted orders and produces interference fringes formed by interference between the pair. The interference contributes to a first grating on the substrate. Overlay error is measured between the grating and the reference structure using diffraction-based or image-based overlay measurements. A phase aberration function for the exit pupil of the lithographic apparatus can then be determined from the measured overlay errors.

Abstract: The present invention relates to methods and systems for designing gauge patterns that are extremely sensitive to parameter variation, and thus robust against random and repetitive measurement errors in calibration of a lithographic process utilized to image a target design having a plurality of features. The method may include identifying most sensitive line width/pitch combination with optimal assist feature placement which leads to most sensitive CD (or other lithography response parameter) changes against lithography process parameter variations, such as wavefront aberration parameter variation. The method may also include designing gauges which have more than one test patterns, such that a combined response of the gauge can be tailored to generate a certain response to wavefront-related or other lithographic process parameters. The sensitivity against parameter variation leads to robust performance against random measurement error and/or any other measurement error.

Abstract: According to an aspect of the present invention, a spectral purity filter includes an aperture, the aperture being arranged to diffract a first wavelength of radiation and to allow at least a portion of a second wavelength of radiation to be transmitted through the aperture, the second wavelength of radiation being shorter than the first wavelength of radiation, wherein the aperture has a diameter greater than 20 ?m.

Abstract: A reflector includes a multi layer mirror structure configured to reflect radiation at a first wavelength, and one or more additional layers. The absorbance and refractive index at a second wavelength of the multi layer mirror structure and the one or more additional layers, and the thickness of the multi layer mirror structure and the one or more additional layers, are configured such that radiation of the second wavelength which is reflected from a surface of the reflector interferes in a destructive manner with radiation of the second wavelength which is reflected from within the reflector.