Abstract: A lithographic exposure system and method for exposing and structuring a substrate coated with a solder resist is provided. The lithographic exposure system having at least one light beam, formed preferably by two or more laser beams of different UV wavelengths, which is deflected relative to the substrate by a variable deflection device, in order to generate structures on the substrate. In particular, the light beam is superimposed, spatially in the image plane and temporally in the exposure, by a spatially limited, high-energy, preferably externally mounted heat source, wherein preferably infrared laser diodes having linear optics are used.

Abstract: Embodiments described herein provide a lithographic system having two or more lithographic tools connected to a radiation source using two or more variable attenuation units. In some embodiments, the variable attenuation unit reflects a portion of the received light beam to the lithographic tool attached thereto and transmits a remaining portion of the received light beam to the lithographic tools downstream. In some embodiments, the radiation source includes two or more laser sources to provide laser beams with an enhanced power level and which can prevent operation interruption due to laser source maintenances and repair.

Abstract: An extreme ultraviolet lithography (EUVL) method includes providing at least two phase-shifting mask areas having a same pattern. A resist layer is formed over a substrate. An optimum exposure dose of the resist layer is determined, and a latent image is formed on a same area of the resist layer by a multiple exposure process. The multiple exposure process includes a plurality of exposure processes and each of the plurality of exposure processes uses a different phase-shifting mask area from the at least two phase-shifting mask areas having a same pattern.

Abstract: Disclosed is a metrology apparatus comprising an optical element configured to receive at or near a pupil plane of the metrology apparatus, at least first radiation comprising a first higher diffracted order and second radiation comprising a zeroth order resulting from illumination of a metrology target with radiation; and to direct said first radiation and second radiation together in a first direction. The metrology apparatus is further configured to form at least a first image of a first interference pattern, the first interference pattern resulting from interference of said first radiation and second radiation at an image plane.

Abstract: The invention relates to a method for exposing at least one stored image (21) on a light-sensitive recording medium (14), with an exposure device (11), which picks up at least one recording medium (14) on a support (12), with at least one exposure head (16, 17), which is moved above the support (12) along a guiding axis (18) in the X direction and the guiding axis (18) and/or the support (12) are moved in the Y direction, with a control system, by which a traversing movement of the at least one exposure head (16, 17) is operated for exposing the at least one image (21) of the recording medium (14) and/or the recording medium (14), wherein the position of the recording medium (14) and/or the position of the at least one image (21) on the recording medium (14) are detected with at least one linear image acquisition device (25), which extends at least partially in the X direction.

Abstract: Embodiments described herein provide a lithographic system having two or more lithographic tools connected to a radiation source using two or more variable attenuation units. In some embodiments, the variable attenuation unit reflects a portion of the received light beam to the lithographic tool attached thereto and transmits a remaining portion of the received light beam to the lithographic tools downstream. In some embodiments, the radiation source includes two or more laser sources to provide laser beams with an enhanced power level and which can prevent operation interruption due to laser source maintenances and repair.

Abstract: Embodiments of the present disclosure provide an apparatus including mask pattern formed on a mask substrate. A plurality of spatial radiation modulators may be vertically displaced from the mask pattern, and distributed across a two-dimensional area. Each of the plurality of spatial radiation modulators may be adjustable between a first transparent state and a second transparent state to control whether radiation transmitted through the mask pattern passes through each of the plurality of spatial radiation modulators.

Abstract: The present invention discloses an apparatus for making direct writing screen plate and a using method thereof. The present invention provides a direct writing screen plate making apparatus and a focal plane control method. A Z-axis controller is used to pre-establish a mapping relation between the focal plane position of the scanning band to be scanned in the next step and the scanning platform position signal. During the next step of scanning, the position of the optical lens is adjusted according to the mapping relation, thus avoiding the problem of inconsistency between the calculated focal plane and the actual focal plane caused by the position deviation between the assembled displacement sensor and the optical lens. The present invention also provides a method for exposing a region of interest and a method for compensating the on-line real-time light uniformity.

Abstract: A spatio-temporally light modulated imaging system for confocal imaging an object includes a light modulating micro-mirror device, an imaging optic, and a camera device, wherein a carrier wheel device is provided for carrying multiple pairs of first and second dichroic beam splitters and multiple pairs of first and second emission filters, wherein the carrier wheel device is adjustable in multiple operational positions relative to the first and second optical axes, and wherein a casing is provided. Furthermore, a carrier wheel device for carrying optical members and a method for confocal imaging an object are disclosed.

Abstract: A method of manufacturing a light emitting device includes: providing a light source including one or more semiconductor laser elements, an optical member including one or more lens parts, a condensing lens, and a photodetector, one above the other; causing at least one semiconductor laser element to emit light; determining a reference detection position of light; placing a first light-shielding member to shield a portion of the light passed through the lens parts; determining a post-shielding detection position; adjusting a distance between the light source and the optical member based on the reference detection position and the post-shielding detection position; and securing the optical member and the light source to each other.

Abstract: A light irradiating device includes a substrate holder configured to hold a substrate; a light irradiating unit; and a power feed unit. The light irradiating unit comprises a light source configured to irradiate light to a surface of the substrate; and a first connector electrically connected with the light source. The power feed unit comprises a power supply module configured to supply a power to the light source; and a second connector electrically connected with the power supply module and configured to be connected to or disconnected from the first connector. The light irradiating unit and the power feed unit are coupled as one body as the first connector and the second connector are connected, and are separated from each other as the first connector and the second connector are disconnected from each other.

Abstract: An exposure apparatus that performs scanning exposure for a substrate is provided. The apparatus comprises a light source, a digital mirror device including a plurality of mirrors capable of controlling a direction of light emitted from the light source and configured to operate to adjust an integrated exposure amount on the substrate in accordance with scanning of the substrate, a projection optical system configured to guide light from the digital mirror device to the substrate and project a pattern onto the substrate, and a controller configured to control the plurality of mirrors in the digital mirror device based on the pattern to be projected onto the substrate, wherein the controller controls the plurality of mirrors such that an integrated exposure amount in an edge portion of the pattern becomes larger than an integrated exposure amount in a portion other than the edge portion.

Abstract: A method includes providing a plurality of fuel droplets into an EUV source vessel by a fuel droplet generator, in which the fuel droplet generator has a first portion inside the EUV source vessel and a second portion outside the EUV source vessel; generating a plurality of output signals respectively from a plurality of oscillation sensors on the fuel droplet generator; determining whether the output signals are acceptable; and determining whether an unwanted oscillation originates from the first portion of the fuel droplet generator or the second portion of the fuel droplet generator when the output signals is determined as unacceptable.

Abstract: Embodiments described herein provide a lithographic system having two or more lithographic tools connected to a radiation source using two or more variable attenuation units. In some embodiments, the variable attenuation unit reflects a portion of the received light beam to the lithographic tool attached thereto and transmits a remaining portion of the received light beam to the lithographic tools downstream. In some embodiments, the radiation source includes two or more laser sources to provide laser beams with an enhanced power level and which can prevent operation interruption due to laser source maintenances and repair.

Abstract: Disclosed is a method of optimizing within an inspection apparatus, the position and/or size (and therefore focus) of a measurement illumination spot relative to a target on a substrate. The method comprises detecting scattered radiation from at least the target resultant from illuminating the target, for different sizes and/or positions of said illumination spot relative to the target; and optimizing said position and/or size of the measurement illumination spot relative to the target based on a characteristic of the detected scattered radiation for the different sizes and/or positions of said illumination spot relative to the target.

Abstract: An optical lithography system is monitored. Information is received from the optical lithography system; a rule is accessed, the rule being associated with one or more of an event in the optical lithography system and an amount of time; a module stored in a library of modules is identified based on the accessed rule; whether a particular condition exists in the optical lithography system is determined using the identified module and the information received from the optical lithography system; and if the particular condition exists, a command signal is generated based on one or more characteristics of the particular condition and provided to an optical source of the optical lithography system. The command signal is based on the determined particular condition, and the command signal is sufficient to change one or more operating parameters of the optical source.

Abstract: A radiation source for a lithographic apparatus, in particular a laser-produced plasma source includes a fan unit surrounding but not obstructing the collected radiation beam that is operated to generate a flow in a buffer gas away from the optical axis. The fan unit can include a plurality of flat or curved blades generally parallel to the optical axis and driven to rotate about the optical axis.

Abstract: A technique involving projecting a pulsed radiation beam using an illumination system onto a region of a plane in a reference frame; using a scanning mechanism to move a calibration sensor relative to the reference frame such that the calibration sensor moves through the beam of radiation in the plane along a scan trajectory; determining a quantity indicative of a velocity of the illumination system relative to the reference frame; and determining information related to a spatial intensity distribution of the radiation beam in the plane in dependence on: (a) an output of the calibration sensor; (b) the scan trajectory of the calibration sensor; and (c) the quantity indicative of a velocity of the illumination system relative to the reference frame.

Abstract: A lithographic apparatus including a monitoring apparatus and an associated monitoring apparatus. The monitoring apparatus is configured for monitoring first radiation of a first wavelength. The monitoring apparatus has a first sensor apparatus including a diamond fluorescent material configured to absorb the first radiation and to emit second radiation being representative of the first radiation, the second radiation being of a second wavelength; and a second sensor apparatus configured to sense the second radiation.

Abstract: The present disclosure is directed to a system for protecting a reflective optic and/or any other surface in a plasma-based illumination system from debris by actively flowing gas against the debris flow direction. According to various embodiments, a vacuum chamber is configured to contain a target material, wherein a laser or discharge produced plasma is generated in response to an excitation of the target material. One or more outlets within the chamber are configured to receive gas flowing from a fluidically coupled gas source and further configured to actively flow the gas towards a source of debris and away from the reflective optic or any other protected surface at a controlled flow rate.

Abstract: The power source device comprises a transformer, a voltage detection unit, a CPU and a drive circuit. Through an applying of a DC voltage, the transformer generates an AC voltage for development of an amplitude corresponding to the voltage value and an applying time of the DC voltage. The voltage detection unit detects a voltage value of the DC voltage. The CPU sets a reference value and generates PWM signals for controlling the applying time in accordance with a difference between the voltage value detected in the voltage detection unit and the reference value. The reference value is a voltage value of the DC voltage when an amplitude of the AC voltage reaches a predetermined value in a predetermined applying time. Controlling the applying time of the DC voltage to the transformer in accordance with the PWM signals, the drive circuit suppress variation in amplitude of the AC voltage.

Abstract: A measurement apparatus including an optical system to provide illumination radiation into a spot on a periodic structure and to receive radiation redirected by the periodic structure, the optical system including a first stop to block zero order radiation from the periodic structure and allow non-zero order radiation to pass, and a second stop to block zero order radiation passing the first stop and to allow the non-zero order radiation to pass, and a radiation detector, downstream of the optical system, to receive the non-zero order radiation.

Abstract: The invention relates to a method for regulating a light source of a photolithography exposure system which comprises a plurality of LEDs, by means of the following steps: the light output of the individual LEDs in specific wavelength ranges is detected, and the detected light output is compared with a desired light output distribution over the entire spectrum. The LEDs are operated such that the desired spectral light output distribution is achieved in the most precise manner possible. The invention also relates to an exposure assembly for a photolithography device, having a light source which comprises a plurality of LEDs, a control means which controls the electrical power supplied to the individual LEDs, and a sensor which can detect the light output of the LEDs in the respective ranges of the wavelengths.

Abstract: Provided is a mask blank substrate being a substrate having two main surfaces, in which one of the two main surfaces of the mask blank substrate on a side on which a transfer pattern is formed has such a surface profile that, when a measurement region of 2.8 mm×2.1 mm of the main surface in a transfer pattern formation region is measured using a white light interferometer under conditions of a pixel number of 640×480, a power spectrum density at a spatial frequency of 1.0×10?2 ?m?1 calculated from a result of the measurement is 6.0×107 nm4 or less.

Abstract: An exposure apparatus includes at least one radiation source, a plurality of projection lenses, and a lens switch. The radiation source is operable for providing a radiation beam. The lens switch is operable for selecting one of the projection lenses to focus the radiation beam to a target plane.

Abstract: A method of controlling a lithographic apparatus, the method including setting an illumination system of the lithographic apparatus to effect a selected illumination mode, measuring a value of a first parameter of the lithographic apparatus, calculating a value of a second parameter of a projected image of a feature of a test pattern having a plurality of features using a model of the lithographic apparatus and the measured value of the first parameter, and controlling the lithographic apparatus with reference to the calculated value of the second parameter.

Abstract: An object of the present invention is to provide a mask blank substrate and the like that enables critical defects to be reliably detected as a result of reducing the number of detected defects, including pseudo defects, even when using highly sensitive defect inspection apparatuses that use light of various wavelengths. The present invention relates to a mask blank substrate that is used in lithography, wherein the power spectral density at a spatial frequency of 1×10?2 ?m?1 to 1 ?m?1, obtained by measuring a 0.14 mm×0.1 mm region on a main surface of the mask blank substrate on the side of which a transfer pattern is formed at 640×480 pixels with a white-light interferometer, is not more than 4×106 nm4, and the power spectral density at a spatial frequency of not less than 1 ?m?1, obtained by measuring a 1 ?m×1 ?m region on the main surface with an atomic force microscope, is not more than 10 nm4.

Abstract: A method for configuring an illumination source of a lithographic apparatus, the method including dividing the illumination source into pixel groups, each pixel group including one or more illumination source points in a pupil plane of the illumination source; changing a polarization state of each pixel group and determining an incremental effect on each of the plurality of critical dimensions resulting from the change of polarization state; calculating a first plurality of sensitivity coefficients for each of the plurality of critical dimensions using the determined incremental effects; selecting an initial illumination source; iteratively calculating a lithographic metric as a result of a change of polarization state using the calculated first plurality of sensitivity coefficients, the change of the polarization state of the pixel group in the initial illumination source creating a modified illumination source; and adjusting the initial illumination source based on the iterative results of calculations.

Abstract: An image forming device includes an image forming unit configured to continuously form images on continuous paper, a conveying unit configured to convey the continuous paper, and a control unit configured to start an image quality adjusting operation for adjusting image quality of a subsequent image to be formed by the image forming unit after formation of a last image by the image forming unit is completed while the conveying unit conveys the continuous paper until the last image arrives at a predetermined position.

Abstract: A source module for use in a lithographic apparatus is constructed to generate extreme ultra violet (EUV) and secondary radiation, and includes a buffer gas configured to cooperate with a source of the EUV radiation. The buffer gas has at least 50% transmission for the EUV radiation and at least 70% absorption for the secondary radiation.

Abstract: A wafer alignment system is provided for performing a unidirectional scan-exposure. The wafer alignment system includes a plurality of wafer stages successively moving from a first position to a second position of a base cyclically. The wafer alignment method also includes an encoder plate having a first opening and a second opening. Further, the wafer alignment system includes a plurality of encoder plate readers and a plurality of wafer stage fiducials on the wafer stages. Further, the wafer alignment system also includes an alignment detection unit above the first opening of the encoder plate.

Abstract: The present invention provides a method of generating, by a computer, data on patterns of a plurality of originals for use in multiple exposure, in which a single-layer pattern is formed on a substrate by exposing the substrate a plurality of times, in an exposure apparatus including an illumination optical system which illuminates an original with light from a light source, and a projection optical system which projects a pattern of the original onto a substrate.

Abstract: The invention is directed to a mask plate, an exposure system comprising a mask plate and an exposing method. The mask plate comprises a light transmitting region, a light shielding region, and a light reflecting region for reflecting exposure light to the light shielding region, with the pattern of the light from the transmitting region and reflecting region corresponding to the pattern of the region exposed to a first and a second substrate respectively. When exposure light irradiates on the mask plate, it passes through the light transmitting region and exposes the first substrate. The light reflecting region reflects the exposure light to a principal reflection structure which further reflects the light for exposing the second substrate. The first and second substrate may be exposed via the same mask plate to minimize waste of exposure light to save production time and efficiency.

Abstract: The present invention relates to an illumination device illuminating an optical gate and projecting an image of the optical gate towards a target surface. The illumination device comprises a light source module generation light, an aperture delimiting the optical gate and a projecting system adapted to image the optical gate at a target surface. The light source module comprises a number of light sources and a number of light collecting means. The light collecting means comprise a central lens aligned along and a peripheral lens at least partially surrounding the central lens. The central lens collects and converts a first part of the light from the light source images the light source between the aperture the projecting system. The peripheral lens part collects and converts a second part of said light from said light source and is adapted to concentrate said second part of said light at said aperture.

Abstract: A system and method for optimizing an illumination source to print a desired pattern of features dividing a light source into pixels and determining an optimum intensity for each pixel such that when the pixels are simultaneously illuminated, the error in a printed pattern of features is minimized. In one embodiment, a method includes selecting a pattern of layout features by determining one or more periodic patterns of features that occurs in the layout database, defining a mathematical relationship between pixel intensities produced by a diffractive optical element and the selected pattern of features, where the mathematical relationship includes a heavier weighting for the periodic patterns of features, and assigning pixel intensities for the diffractive optical element using the mathematical relationship, where the pixel intensities are calculated to print the periodic features with greater image fidelity in proportion to the heavier weighting.

Abstract: A contaminant trap is used in an EUV radiation source apparatus. An EUV radiation beam is generated and focused through a low pressure gaseous atmosphere into a virtual source point. The EUV radiation creates a plasma in the low pressure hydrogen atmosphere through which it passes. A contaminant trap including electrodes is located in or around radiation beam as it approaches the virtual source point. A DC biasing source is connected to the electrodes to create an electric field oriented to deflect out of the beam path contaminant particles that have been negatively charged by the plasma. Additional RF electrodes and/or an ionizer enhance the plasma to increase the charging of the particles. The deflecting electrodes can be operated with RF bias for a short time, to ensure dissipation of the enhanced plasma.

Abstract: The invention relates to a method and device for calibrating or testing the detector surface (10) of a measuring device (1) detecting hydrometeors. According to the method, impulses are focussed on the detector surface (10) in a controlled manner, the responses caused by the impulses, detected by the detector of the measuring device (1), are measured, the measurement values of the responses are compared with the target values and the required corrections to the settings of the measuring device (1) are analyzed, and the measuring device (1) is adjusted on the basis of the analysis. According to the invention, an electromagnetic radiation pulse (70) of short duration is focussed on the detector surface (10), whereby this causes a thermal-expansion reaction in the detector surface (10), detected by the detector.

Abstract: The present invention provides an image reader apparatus capable of obtaining an image having stable brightness while suppressing an increase of the cost of the apparatus. The image reader apparatus 1 for reading an image on a document 2 being fed and outputting an image signal includes a synchronization signal generation circuit 4 for generating a synchronization signal SS synchronous with a feed timing and a feed cycle of the document 2, a CCD 6 for reading an image on the document 2 in synchronism with the synchronization signal SS, an LED 9 for emitting white light, and a lighting control circuit 7 for turning the LED 9 on in synchronism with the synchronization signal SS and turning the light source off so that a lighting period is equalized for each line irrespective of a variation of the feed cycle of the document 2. The lighting control circuit 7 turns the LED 9 off so that the lighting period of the LED 9 is equal to a predetermined preset period.

Abstract: The present invention provides a drawing apparatus for performing drawing on a substrate with a charged particle beam, the apparatus comprising an optical system configured to irradiate the substrate with the charged particle beam, a substrate stage configured to hold the substrate, an aperture member provided with the substrate stage, a detector configured to detect a charged particle beam having passed through an aperture of the aperture member, and a support configured to support the detector, wherein the support and the substrate stage are separated from each other.

Abstract: The generation of EUV light includes rotating a cylinder at least partially coated with a plasma-forming target material, directing pulsed illumination to a first set of helically-arranged spots traversing a material-coated portion of the rotating cylinder in a first direction and directing pulsed illumination to a second set of helically-arranged spots traversing the material-coated portion of the rotating cylinder in a second direction, the pulsed illumination being suitable for exciting the plasma-forming target material.

Abstract: The technology disclosed relates to improved acousto-optic deflectors (AODs). In particular, it relates to compensation for subtle effects not previously addressed by AOD designers. A shifting center of gravity is described and addressed using advanced power equalization strategies. Denser writing brushes are provided by using a two-dimensional array of beams with corrections for factors such as angle of incidence at the AOD interface.

Abstract: In a projection exposure method for the exposure of a radiation-sensitive substrate arranged in the region of an image surface of a projection objective with at least one image of a pattern of a mask arranged in the region of an object surface of the projection objective, laser radiation having a spectral intensity distribution I(?) dependent on the angular frequency ? is used. The laser radiation is characterized by an aberration parameter ? in accordance with: ? := ? I ? ( ? ) ? ? 2 ? ? ? ? I ? ( ? ) ? ? ? and a coherence time ? in accordance with: ? = ? I ? ( ? ) 2 ? ? ? [ ? I ? ( ? ) ? ? ? ] 2 The laser radiation is introduced into an illumination system for generating an illumination radiation directed onto the mask, and the pattern is imaged onto the substrate with the aid of a projection objective. The spectral intensity distribution is set so that ??2?0.3.

Abstract: A light source device including a seed light generation device, a light amplification unit which optically amplifies seed light generated by the seed light generation device, and a wavelength conversion unit which converts the wavelength of the light optically amplified by the light amplification unit. The seed light generation device includes a pulsed light generation unit which generates pulsed light having a single wavelength, a pulse modulation unit which selectively passes and extracts a part of the pulsed light, and a timing adjustment unit which relatively adjusts the extracting timing of the pulsed light by the pulse modulation unit during the generation period of the pulsed light by the pulse generation unit, according to an operation.

Abstract: An exposure apparatus capable of preventing a reduction in its accuracy due to, for example, the influence of aging or the influence of heat is disclosed. Also disclosed is a method of controlling the same, and an alignment method for exposure. In one aspect, the exposure apparatus includes a main stage for adjusting a position of a substrate, a beam irradiation unit for irradiating a beam onto a mask, and a beam monitoring unit having a position fixed with respect to the main stage, and for recognizing the beam emitted from the beam irradiation unit and passed through one pattern of the mask.

Abstract: In an immersion lithographic apparatus, bubble formation in immersion liquid is reduced or prevented by reducing a gap size or area on a substrate table. The gap size is reduced using an edge member which may be, for example, a ring known as a BES (Bubble Extraction System) ring. Information regarding the shape and/or cross-sectional dimension (e.g., diameter) of the substrate, or information regarding the size of the gap, is transmitted to a controller that controls the edge member in order for the edge member, for example, to be reduced to an appropriate size to reduce the gap as much as possible, desirably without compressing the edge of the substrate. Alternatively or additionally, the gap may be reduced by moving the substrate and/or edge member adjacent the edge of a surface of the substrate table.

Abstract: A maskless lithography system for transferring a pattern onto the surface of a target. At least one beam generator for generating a plurality of beamlets. A plurality of modulators modulate the magnitude of a beamlet, and a control unit controls of the modulators. The control unit generates and delivers pattern data to the modulators for controlling the magnitude of each individual beamlet. The control unit includes at least one data storage for storing the pattern data, at least one readout unit for reading out the data from the data storage, at least one data converter for converting the data that is read out from the data storage into at least one modulated light beam, and at least one optical transmitter for transmitting the at least one modulated light beam to the modulation modulators.

Abstract: A lithographic system includes a source configured to generate a radiation, the source including a cathode and an anode, the cathode and the anode configured to create a discharge in a fuel located in a discharge space so as to generate a plasma, the discharge space including, in use, a substance configured to adjust radiation emission by the plasma so as to control a volume defined by the plasma; a pattern support configured to hold a patterning device, the patterning device configured to pattern the radiation to form a patterned beam of radiation; a substrate support configured to support a substrate; and a projection system configured to project the patterned beam of radiation onto the substrate.

Abstract: A dichroic mirror configured to separate a first type of radiation in a first wavelength range having an upper boundary from a second type of radiation in a second wavelength range having a lower boundary greater than the upper boundary of the first wavelength. The mirror includes a substrate, and a stack having a reflective surface facing away from the substrate and a width that increases stepwise in a direction towards the substrate. The stack is formed by alternating layers of first and second materials on the substrate. The reflective surface has steps with a width greater than the upper boundary of the first wavelength and less than the lower boundary of the second wavelength.

Abstract: A method and system for photolithography is provided. The system includes a photoresist comprising a photoinitiator and a prepolymer resin. The system further includes a first light source operable to generate at least a first beam of light which is focused on a first area of the photoresist. The first beam of light is configured to excite the photoinitiator. The system further includes a second light source operable to generate at least a second beam of light which is focused on a second area of the photoresist, the second beam of light configured to deactivate at least temporarily the photoinitiator excited by the first beam of light. The first area and second area overlap at least partially. A time difference of at least 10 ns exists between the photoinitiator being excited by the first beam of light and the photoinitiator initiating polymerization.

Abstract: A lithographic apparatus comprises an illumination system for supplying a beam of radiation, a patterning arrangement incorporating an array of individually controllable elements for imparting a pattern to the beam cross-section, a substrate table for supporting a substrate, and a projection system incorporating a microlens array for projecting the beam onto a target portion of the substrate. An error compensator is provided for supplying error correction values for compensating for the effect of positional errors in the microlens array, and a grey scale modulator is provided for supplying drive signals to controllable elements of the patterning arrangement in dependence on the error correction values in order to compensate for the effect of positional errors in the microlens array by varying the intensity of some parts of the pattern relative to other parts of the pattern.