Abstract: A spectroscopic scatterometer detects both zero order and higher order radiation diffracted from an illuminated spot on a target grating. The apparatus forms and detects a spectrum of zero order (reflected) radiation, and separately forms and detects a spectrum of the higher order diffracted radiation. Each spectrum is formed using a symmetrical phase grating, so as to form and detect a symmetrical pair of spectra. The pair of spectra can be averaged to obtain a single spectrum with reduced focus sensitivity. Comparing the two spectra can yield information for improving height measurements in a subsequent lithographic step. The target grating is oriented obliquely so that the zero order and higher order radiation emanate from the spot in different planes. Two scatterometers can operate simultaneously, illuminating the target from different oblique directions. A radial transmission filter reduces sidelobes in the spot and reduces product crosstalk.

Abstract: Metrology targets are formed by a lithographic process, each target comprising a bottom grating and a top grating. Overlay performance of the lithographic process can be measured by illuminating each target with radiation and observing asymmetry in diffracted radiation. Parameters of metrology recipe and target design are selected so as to maximize accuracy of measurement of overlay, rather than reproducibility. The method includes calculating at least one of a relative amplitude and a relative phase between (i) a first radiation component representing radiation diffracted by the top grating and (ii) a second radiation component representing radiation diffracted by the bottom grating after traveling through the top grating and intervening layers. The top grating design may be modified to bring the relative amplitude close to unity. The wavelength of illuminating radiation in the metrology recipe can be adjusted to bring the relative phase close to ?/2 or 3?/2.

Abstract: A second set of superimposed gratings are superposed over a first set of superimposed gratings. The second set of gratings have a different periodicity from the first set of gratings or a different orientation. Consequently the first order diffraction pattern from the second set of superimposed gratings can be distinguished from the first order diffraction pattern from the first set of superimposed gratings.

Abstract: The overlay error of a target in a scribelane is measured. The overlay error of the required feature in the chip area may differ from this due to, for example, different responses to the exposure process. A model is used to simulate these differences and thus a more accurate measurement of the overlay error of the feature determined.

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: A lithographic projection apparatus includes a support structure configured to hold a patterning device, the patterning device configured to pattern a beam of radiation according to a desired pattern; 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; and a shutter configured to isolate the space from the substrate or a space to be occupied by a substrate.

Abstract: A multi-stage system includes a stator including a plurality of electric coils; a first stage including a first magnet assembly, the first stage moveable relative to the stator; a second stage including a second magnet assembly, the second stage moveable relative to the stator; a controller configured to position the first and the second stage relative to the stator by activating, respectively, a first subset of the plurality of electric coils to interact with the first magnet assembly and a second subset of the plurality of electric coils to interact with the second magnet assembly, the controller adapted to prevent at least one electric coil, to be simultaneously shared by the first and the second subset to position the first and the second stage on the stator, from activating.

Abstract: A method of determining focus of a lithographic apparatus has the following steps. Using the lithographic process to produce first and second structures on the substrate, the first structure has features which have a profile that has an asymmetry that depends on the focus and an exposure perturbation, such as dose or aberration. The second structure has features which have a profile that is differently sensitive to focus than the first structure and which is differently sensitive to exposure perturbation than the first structure. Scatterometer signals are used to determine a focus value used to produce the first structure. This may be done using the second scatterometer signal, and/or recorded exposure perturbation settings used in the lithographic process, to select a calibration curve for use in determining the focus value using the first scatterometer signal or by using a model with parameters related to the first and second scatterometer signals.

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: A transmissive spectral purity filter is configured to transmit extreme ultraviolet radiation. The spectral purity filter includes a filter part having a plurality of apertures configured to transmit extreme ultraviolet radiation and to suppress transmission of a second type of radiation. Each aperture has been manufactured by an anisotropic etching process.

Abstract: A map of the surface of a substrate is generated at a measurement station. The substrate is then moved to where a space between a projection lens and the substrate is filled with a liquid. The substrate is then aligned using, for example, a transmission image sensor and, using the previous mapping, the substrate can be accurately exposed. Thus the mapping does not take place in a liquid environment.

Abstract: A lithographic apparatus has a support that is provided with burls for holding an object. The support has been fabricated with a lithographic manufacturing method, e.g., a MEMS-technology, so as to create burls whose orientations or positions are individually electrically controllable.

Abstract: In a lithographic apparatus, a scanning mechanism is coarse compared with precise patterns to be exposed onto a substrate. In order to ensure that the image and the substrate are aligned at some point in time, an oscillation is imparted to either the substrate table, or to a device that aligns the image, such as a mask table. The oscillation frequency is chosen to compliment a maximum alignment error. The frequency of a radiation pulse is arranged to coincide with the image and the substrate being most accurately aligned. The radiation pulse of the image may be timed to coincide with the alignment without the use of the imparted oscillation.

Abstract: A seal between a table and a component in a lithographic apparatus is disclosed. The seal bridges a gap between the component and the table when the component is in a position relative to the table. The component is moveable, in use, relative to the table and in an embodiment is attached to the table. The seal may be integral with the component or the table.

Abstract: A spectral purity filter is configured to allow transmission therethrough of extreme ultraviolet (EUV) radiation and to refract or reflect non-EUV secondary radiation. The spectral purity filter may be part of a source module and/or a lithographic apparatus.

Abstract: A beam delivery apparatus is used with a laser produced plasma source. The beam delivery apparatus comprises variable zoom optics (550) operable to condition a beam of radiation so as to output a conditioned beam having a configurable beam diameter (b) and a plurality of mirrors (530a, 530b) operable to direct the conditioned beam of radiation to a plasma generation site. The beam delivery apparatus enables control of the axial position of the beam where the beam has a particular diameter, with respect to the beam's focus position (570). Also, a method is used to control the axial position of the location at a plasma generation site where a beam has a particular diameter, with respect to the beam's focus position.

Abstract: Disclosed is a substrate support for an apparatus of the type which projects a beam of EUV radiation onto a target portion of a substrate (400). The substrate support comprises a substrate table constructed to hold the substrate, a support block (420) for supporting the substrate table, and a cover plate (450?) disposed around the substrate table. The top surface of the cover plate and the top surface of a substrate mounted on the substrate table are all substantially at the same level. At least one sensor unit (430) is located on the substrate support and its top surface is also at the same level as that of the cover plate and substrate. Also disclosed is an EUV lithographic apparatus comprising such a substrate support.

Abstract: A pattern from a patterning device is applied to a substrate by a lithographic apparatus. The applied pattern includes product features and metrology targets. The metrology targets include large targets which are for measuring overlay using X-ray scattering and small targets which are for measuring overlay by diffraction of visible radiation. Some of the smaller targets are distributed at locations between the larger targets, while other small targets are placed at the same locations as a large target. By comparing values measured using a small target and large target at the same location, parameter values measured using all the small targets can be corrected for better accuracy. The large targets can be located primarily within scribe lanes while the small targets are distributed within product areas.

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 lithographic apparatus includes an illumination system for providing a beam of extreme ultra-violet radiation, a masking device for controlling the illumination of a patterning device by the beam of radiation, a support for supporting the patterning device, the patterning device configured to impart a pattern to the beam of radiation, a substrate table for holding a substrate, and a projection system for projecting the patterned beam of radiation onto a target portion of the substrate. The masking device includes a masking blade including a masking edge configured to delimit a boundary of an illumination region on the patterning device. The masking blade is configured to reflect extreme ultra-violet radiation incident on the masking blade such that at least a portion of the reflected radiation is not captured by the projection system.