NL1035920A1 - Lithographic System, Lithographic Apparatus and Device Manufacturing Method. - Google Patents

Description

Lithographic System, Lithographic Apparatus and Device Manufacturing Method

FIELD

The present invention relates to a lithographic system, a lithographic apparatus forming part of the lithographic system, and a method for manufacturing a device.

BACKGROUND A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In that instance, a patterning device, which is alternatively referred to as a mask or a reticle, may be used to generate a circuit pattern to be formed on an individual layer of the IC. This pattern can be transferred onto a target portion (e.g. comprising part of, one, or several dies) on a substrate (e.g. a silicon wafer). Transfer of the pattern is typically via imaging onto a layer of radiation-sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of adjacent target portions that are successively patterned. Known lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing an entire pattern onto the target portion at one time, and so-called scanners, in which each target portion is irradiated by scanning the pattern through a radiation beam in a given direction (the "scanning"-direction) while synchronously scanning the substrate parallel or anti parallel to this direction. A problem arises where it is desired to print part of a desired pattern on the substrate at the highest possible resolution, when other parts of the desired pattern can be printed at a much lower resolution. This situation arises, for example, in a layer of an IC in which the core of a desired IC pattern comprises dense parallel gate lines while the periphery of that pattern includes much larger structures which contact the gate lines. A single, high resolution lithographic apparatus can be used to print both the core of the pattern and the periphery of the pattern in a single exposure. The lithographic apparatus comprises an illumination system configured to illuminate the patterning device with a beam of radiation. Within a typical illumination system, the beam is shaped and controlled such that at a pupil plane of the illumination system the beam has a desired spatial intensity distribution. The spatial intensity distribution at the pupil plane effectively acts as a virtual radiation source to provide illumination radiation at the patterning device level. Various illumination modes (i.e. shapes of the intensity distribution) can be used, such as "conventional illumination" (a top-hat discshaped intensity distribution in the pupil) and/or "off-axis illumination" (e.g., annular, dipole, quadrupole or more complex shaped arrangements of the illumination pupil intensity distribution). For printing the periphery including the larger structures conventional illumination would be desired, whereas for printing the dense lines in the core of the pattern a dipole illumination mode would be desired. In view of the incompatibility of these two illumination modes, there is the problem of having to provide an illumination mode which deviates from any of the desired illumination modes.

SUMMARY A possibility for the printing of a combination of dense structures surrounded by less dense structures is the use of a high resolution lithographic apparatus to print the core of the pattern, with a low resolution lithographic apparatus being used to print the periphery of the pattern. In particular, a lithographic apparatus including a high numerical aperture (NA) objective arranged to transfer a pattern of a patterning device onto a substrate via imaging at a four times reduction, together with a corresponding high NA illumination system arranged to provide dipole illumination of the patterning device may be used to image the dense line structures while a lithographic apparatus including a four times reduction objective with a lower numerical aperture in combination with a corresponding lower NA illumination system may be used to image the peripheral structure. Such an arrangement has a disadvantage, however, of the use of two costly lithographic apparatus. The high resolution lithographic apparatus may not be suitable for printing the relatively large structures of the periphery in view of an inefficient machine usage. A possibility for printing dense lines at high resolution is the use of interferometric lithography, that is the use of an apparatus arranged to provide a standing wave pattern produced by an interference of two or more coherent optical beams, to produce the pattern on the substrate. United States Patent No. US 6,233,044 discloses a lithographic apparatus for producing a pattern on a semiconductor wafer in which some of the spatial frequency components are derived by conventional optical lithography and some by interferometric lithographic techniques.

The apparatus comprises a beamsplitter before the mask illumination (i.e., a beamsplitter disposed upstream of the mask) and two optical paths, and a first imaging optical path, traversing a first imaging optical system, that images diffracted beams corresponding to a high-frequency subset of the mask image onto the wafer die. The apparatus further includes a second reference optical path that provides a reference beam at the wafer die or target portion (for providing interference). The reference beam is incident on the substrate off-axis with respect to the first imaging optical path. In order to avoid exposure of adjacent wafer areas, the reference beam is shaped by a second imaging system containing a field stop for delimiting the exposure area. The shaping is accomplished by arranging the field stop and the second imaging system such as to provide imaging at an astigmatic demagnification of the field stop. Such an arrangement suffers a disadvantage however that a field stop arrangement suitable for use with astigmatic magnification is difficult to implement.

It is desirable, for example, to provide a lithographic system incorporating an interferometric lithographic apparatus which may be used to produce the most dense portion of a pattern on a substrate wherein the scanning of the substrate to expose subsequent portions of a pattern on different regions of the substrate is made possible.

According to an aspect of the invention, there is provided a lithographic system comprising a lithographic system comprising: a first lithographic apparatus configured to project a patterned radiation beam onto a target portion of a substrate; and a second lithographic apparatus comprising: an illumination system configured to condition a radiation beam, an interferometric arrangement comprising a beam splitting arrangement configured to split the radiation beam into split beams and a recombination arrangement configured to recombine the split beams so as to produce an interference pattern at a field plane, a masking arrangement configured to selectively transmit a portion of the interference pattern, a substrate table configured to hold the substrate, and a projection system configured to project the selectively transmitted portion of the interference pattern onto a selected area of the target portion of the substrate.

According to an aspect of the invention, there is provided an apparatus comprising: an illumination system configured to condition a radiation beam; an interferometric arrangement configured to split the radiation beam and to recombine the split beams so as to produce an interference pattern at a field plane; a masking arrangement configured to selectively transmit a portion of the interference pattern; a substrate table configured to hold the substrate; and a projection system configured to project the selectively transmitted portion of the interference pattern onto a target portion of the substrate.

According to an aspect of the invention, there is provided a device manufacturing method comprising: using a first lithographic apparatus: to condition a radiation beam, to impart the radiation beam with a pattern in its cross-section to form a patterned radiation beam, and to project the patterned radiation beam onto a first target portion of the substrate; and using a second lithographic apparatus: to condition a radiation beam, to split the radiation beam and to recombine the split beams so as to produce an interference pattern at a field plane, to selectively transmit a portion of the interference pattern, and to project the selectively transmitted portion of the interference pattern onto a second target portion of the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which: - Figure 1 depicts an optical lithographic apparatus for use in a lithographic system according to an embodiment of the invention; - Figure 2 depicts an interferometric lithographic apparatus for use in the lithographic system; - Figure 3 depicts a masking arrangement incorporated in the field plane of the apparatus of Figure 2; and - Figure 4 discloses a process used to produce a patterned substrate using the apparatus as depicted in Figures 1 and 2.

DETAILED DESCRIPTION

In accordance with an embodiment of the invention, a lithographic apparatus is used to image a first pattern of a patterning device on the periphery of a target portion, this pattern corresponding to relatively large features, which can be printed at a relatively low resolution, at the periphery of, for example, an IC layer pattern. An interferometric lithographic apparatus is then used to print more detailed structures at the core of the target portion corresponding to relatively small features at the core of the, for example, IC layer pattern.

Figure 1 schematically depicts an optical lithographic apparatus for use in a lithographic system according to one embodiment of the invention, this apparatus being used to image the desired pattern (i.e., said first pattern) on the periphery of the target portion.

The apparatus comprises: an illumination system (illuminator) IL configured to condition a radiation beam B (e.g. UV radiation or DUV radiation); a support structure (e.g. a mask table) MT constructed to support a patterning device (e.g. a mask) MA and connected to a first positioner PM configured to accurately position the patterning device in accordance with certain parameters; a substrate table (e.g. a wafer table) WT constructed to hold a substrate (e.g. a resist coated wafer) W and connected to a second positioner PW configured to accurately position the substrate in accordance with certain parameters; and a projection system (e.g. a refractive projection lens system) PL configured to project a pattern imparted to the radiation beam B by patterning device MA onto a target portion C (e.g. comprising one or more dies) of the substrate W.

The illumination system may include various types of optical components, such as refractive, diffractive or reflective, types of optical components, or any combination thereof, for directing, shaping, or controlling radiation.

The support structure MT holds the patterning device in a manner that depends on the orientation of the patterning device, the design of the lithographic apparatus, and other conditions, such as for example whether or not the patterning device is held in a vacuum environment. The support structure MT can use mechanical, vacuum, electrostatic or other clamping techniques to hold the patterning device. The support structure MT may be a frame or a table, for example, which may be fixed or movable as required. The support structure MT may ensure that the patterning device is at a desired position, for example with respect to the projection system. Any use of the terms "reticle" or "mask" herein may be considered synonymous with the more general term "patterning device."

The term "patterning device" used herein should be broadly interpreted as referring to any device that can be used to impart a radiation beam with a pattern in its cross-section such as to create a pattern in a target portion of the substrate. It should be noted that the pattern imparted to the radiation beam may not exactly correspond to the desired pattern in the target portion of the substrate, for example if the pattern includes phase-shifting features or so called assist features. Generally, the pattern imparted to the radiation beam will correspond to a particular functional layer in a device being created in the target portion, such as an integrated circuit.

The patterning device may be transmissive or reflective. Examples of patterning devices include masks, programmable mirror arrays, and programmable LCD panels. Masks are well known in lithography, and include mask types such as binary, alternating phase-shift, and attenuated phase-shift, as well as various hybrid mask types. An example of a programmable mirror array employs a matrix arrangement of small mirrors, each of which can be individually tilted so as to reflect an incoming radiation beam in different directions. The tilted mirrors impart a pattern in a radiation beam which is reflected by the mirror matrix.

The term "projection system" used herein should be broadly interpreted as encompassing any type of projection system, including refractive, reflective, or catadioptric optical systems, or any combination thereof, as appropriate for the exposure radiation being used, or for other factors such as the use of an immersion liquid or the use of a vacuum. Any use of the term "projection lens" herein may be considered as synonymous with the more general term "projection system". As here depicted, the apparatus is of a transmissive type (e.g. employing a transmissive mask). Alternatively, the apparatus may be of a reflective type (e.g. employing a programmable mirror array of a type as referred to above, or employing a reflective mask).

The lithographic apparatus may be of a type having two (dual stage) or more substrate tables (and/or two or more patterning device support structures). In such "multiple stage" machines the additional tables and/or support structures may be used in parallel, or preparatory steps may be carried out on one or more tables and/or support structures while one or more other tables and/or support structures are being used for exposure.

The lithographic apparatus may also be of a type wherein at least a portion of the substrate may be covered by a liquid having a relatively high refractive index, e.g. water, so as to fill a space between the projection system and the substrate. Immersion techniques are well known in the art for increasing the numerical aperture of projection systems. The term "immersion" as used herein does not mean that a structure, such as a substrate, must be submerged in liquid, but rather only means that liquid is located between the projection system and the substrate during exposure.

Referring to Figure 1, the illuminator IL receives a radiation beam from a radiation source SO. The source and the lithographic apparatus may be separate entities, for example when the source is an excimer laser. In such cases, the source is not considered to form part of the lithographic apparatus and the radiation beam is passed from the source SO to the illuminator IL with the aid of a beam delivery system BD comprising, for example, suitable directing mirrors and/or a beam expander. In other cases the source may be an integral part of the lithographic apparatus, for example when the source is a mercury lamp. The source SO and the illuminator IL, together with the beam delivery system BD if required, may be referred to as a radiation system.

The illuminator IL may comprise an adjuster AD to adjust the angular intensity distribution of the radiation beam. Generally, at least the outer and/or inner radial extent (commonly referred to as σ-outer and σ-inner, respectively) of the intensity distribution in a pupil plane of the illuminator can be adjusted. In addition, the illuminator IL may comprise various other components, such as an integrator IN and a condenser CO. The illuminator may be used to condition the radiation beam, to have a desired uniformity and intensity distribution in its cross section.

The radiation beam B is incident on the patterning device (e.g., mask MA), which is held on the support structure (e.g., mask table) MT, and is patterned by the patterning device. Having traversed the patterning device MA, the radiation beam B passes through the projection system PL, which focuses the beam onto a target portion C of the substrate W. With the aid of the second positioner PW and position sensor IF (e.g. an interferometric device, linear encoder or capacitive sensor), the substrate table WT can be moved accurately, e.g. so as to position different target portions C in the path of the radiation beam B. Similarly, the first positioner PM and another position sensor (which is not explicitly depicted in Figure 1) can be used to accurately position the patterning device MA with respect to the path of the radiation beam B, e.g. after mechanical retrieval from a mask library, or during a scan. In general, movement of the patterning device support structure MT may be realized with the aid of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning), which form part of the first positioner PM. Similarly, movement of the substrate table WT may be realized using a long-stroke module and a short-stroke module, which form part of the second positioner PW. In the case of a stepper (as opposed to a scanner) the patterning device support structure MT may be connected to a short-stroke actuator only, or may be fixed. Patterning device MA and substrate W may be aligned using patterning device alignment marks Ml, M2 and substrate alignment marks PI, P2. Although the substrate alignment marks as illustrated occupy dedicated target portions, they may be located in spaces between target portions (these are known as scribe-lane alignment marks). Similarly, in situations in which more than one die is provided on the patterning device MA, the patterning device alignment marks may be located between the dies. The depicted apparatus could be used in at least one of the following modes: 1. In step mode, the patterning device support structure MT and the substrate table WT are kept essentially stationary, while an entire pattern imparted to the radiation beam is projected onto a target portion C at one time (i.e. a single static exposure). The substrate table WT is then shifted in the X and/or Y direction so that a different target portion C can be exposed. In step mode, the maximum size of the exposure field limits the size of the target portion C imaged in a single static exposure. 2. In scan mode, the patterning device support structure MT and the substrate table WT are scanned synchronously while a pattern imparted to the radiation beam is projected onto a target portion C (i.e. a single dynamic exposure). The velocity and direction of the substrate table WT relative to the patterning device support structure MT may be determined by the (de-)magnification and image reversal characteristics of the projection system PL. In scan mode, the maximum size of the exposure field limits the width (in the non-scanning direction) of the target portion in a single dynamic exposure, whereas the length of the scanning motion determines the height (in the scanning direction) of the target portion. 3. In another mode, the patterning device support structure MT is kept essentially stationary holding a programmable patterning device, and the substrate table WT is moved or scanned while a pattern imparted to the radiation beam is projected onto a target portion C. In this mode, generally a pulsed radiation source is employed and the programmable patterning device is updated as required after each movement of the substrate table WT or in between successive radiation pulses during a scan. This mode of operation can be readily applied to maskless lithography that utilizes programmable patterning device, such as a programmable mirror array of a type as referred to above.

Combinations and/or variations on the above described modes of use or entirely different modes of use may also be employed.

Figure 2 schematically depicts an interferometric lithographic apparatus for use in the lithographic system according to an embodiment of the invention. In the Figure, features which are generally equivalent to the features of the apparatus shown in Figure 1 are labeled accordingly. However, the source, SO', beam delivery system, BD', and illuminator, IL', differ from the respective components SO, BD and IL shown in the apparatus of Figure 1 in that they are arranged to provide a low sigma coherent illumination system. The low sigma coherent illumination system may, for example, include a laser and laser beam shaping optics providing a collimated beam of laser radiation having a value of sigma σ of less than 0.05. Such a system may be made to be considerably cheaper than a conventional variable sigma illumination system.

The lithographic apparatus of Figure 2 also varies from the apparatus shown in Figure 1 in that the patterning device, MA, is replaced by an interferometric system comprising a beam splitter in the form of a grating, GR, and a beam recombination system in the form of mirrors Ml and M2, to recombine the beams produced by the grating, GR. The interferometric system is arranged such that the beam produced by the illuminator IL' produces an interference pattern at a field plane, FP, where the recombined beams BG1 and BG2 interfere, the position of the field plane FP being displaced along the optical axis (shown as a dotted line in Figure 2) relative to the position of the patterning device MA in the apparatus of Figure 1. The interference pattern at the plane FP is imaged by the projection system PL' onto the core of a target portion at the substrate W. A numerical aperture NA' of the radiation beams at the field plane FP (in accordance with the angle A in Figure 2) may have a value in the range of 0.8 - 0.9. The value of NA', however, is not limited to this range and can be arranged at any desired value by adjustment of the mirror position and orientation of mirrors Ml and M2, or of only mirror Ml or M2. A field masking system, in the form of a masking blade system, MB, is provided at or near the field plane, FP. A stop S constructed and arranged to block one or more undesired diffracted orders of radiation emanating from the grating GR, such as residual zeroth order diffracted radiation, is positioned adjacent to the grating GR.

As illustrated in Figure 3, the masking blade MB may include four blades, Bl, B2, B3, B4, which are each movable in the XY plane so as to define between them an aperture AP. During exposure of a target portion, a controller arranged to move the blades B1 and B3 along the Y-direction, moves the blades B1 and B3 such as to open and close the aperture AP synchronously with the scanning stage to delimit an exposed area along the Y-direction. The aperture AP, as shaped by the masking blade system MB, is imaged onto the target portion to delimit the core area of the target portion where the interference pattern is printed. Only a portion of the interference pattern produced at the field plane, FP, is transmitted to the projection system, PL'. The projection system, PL', is arranged to have a two times demagnification so as to provide imaging at substrate level at a numerical aperture NA" which may have a value in the range of 1.6-1.8 (in accordance with the range of NA' mentioned above). The projection system PL' can be embodied as an immersion projection system for use with immersion liquid, disposed between the projection system and an exposed target portion on the substrate and having a refractive index in the range of 1.5 to 2.0. It will be appreciated that due to the demagnification DM of minus two times, DM = -2, produced by the projection system, PL', to open and close the aperture AP produced in the masking blade system, MB, the blades B1 and B3 should be moved at twice the velocity of the scanning speed of the substrate table WT. Since the interferometric apparatus will usually be used only to print the relatively small core area of the target portion of a substrate W, such as an area of 5 mm x 5 mm there will be time to accelerate the blades B1 and B3 in the masking blade system, MB, to the desired speed. A system for enabling the synchronization of the movement across the interference pattern at the field plane with the scanning movement of the substrate is described, for example, in United States Patent No. US 6,882,477.

Turning now to Figure 4, it will be seen that by combination of the use of the conventional lithographic apparatus of Figure 1, and the interferometric apparatus of Figure 2, it is possible to print, for example, a complete IC layer pattern on a target portion on the substrate W. For example, a lithographic apparatus of Figure 1 may be used to expose the periphery of each target portion on the substrate with the corresponding pattern. Next the exposed substrate is transferred by a substrate handling system to the interferometric lithographic apparatus as illustrated in

Figure 2. Subsequently, the core of each target portion on the substrate is exposed to the corresponding pattern of the core (alternatively, the core could be exposed first and the periphery exposed second). Next, the substrate is transported by a substrate handling system to a substrate track apparatus for post exposure processing and resist development.

It will be appreciated that in the particular example shown and described, the demagnification of the projection system, PL, is chosen to be minus two times. However, the demagnification of the projection system PL' can take any suitable value in accordance with the maximum obtainable numerical aperture NA' at the field plane FP and the selected numerical aperture NA" at substrate level.

It will be appreciated that while it is convenient for the beam splitter to comprise a grating GR, there are other possibilities for beam splitters such as a dichroic surface. Furthermore, the recombination mechanism Ml, M2 to recombine the split beams may take other forms, for example a prism arrangement instead of or in addition to a mirror.

It will also be appreciated that while the optical lithographic apparatus and the interferometric lithographic apparatus have been described as entirely separate apparatus, it may be possible to combine the two apparatus with appropriate portions of the combined apparatus being adjustable to provide the required functionality.

Although specific reference may be made in this text to the use of lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein may have other applications, such as the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat-panel displays, liquid-crystal displays (LCDs), thin film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms "wafer" or "die" herein may be considered as synonymous with the more general terms "substrate" or "target portion", respectively. The substrate referred to herein may be processed, before or after exposure, in for example a track (a tool that typically applies a layer of resist to a substrate and develops the exposed resist), a metrology tool and/or an inspection tool. Where applicable, the disclosure herein may be applied to such and other substrate processing tools. Further, the substrate may be processed more than once, for example in order to create a multi-layer IC, so that the term substrate used herein may also refer to a substrate that already contains multiple processed layers.

Although specific reference may have been made above to the use of embodiments of the invention in the context of optical lithography, it will be appreciated that the invention may be used in other applications, for example imprint lithography, and where the context allows, is not limited to optical lithography. In imprint lithography a topography in a patterning device defines the pattern created on a substrate. The topography of the patterning device may be pressed into a layer of resist supplied to the substrate whereupon the resist is cured by applying electromagnetic radiation, heat, pressure or a combination thereof. The patterning device is moved out of the resist leaving a pattern in it after the resist is cured.

The terms "radiation" and "beam" used herein encompass all types of electromagnetic radiation, including ultraviolet (UV) radiation and DUV radiation (e.g. having a wavelength of or about 365, 355, 248, 193, 157 or 126 nm).

The term "lens", where the context allows, may refer to any one or combination of various types of optical components, including refractive, reflective, magnetic, electromagnetic and electrostatic optical components.

While specific embodiments of the invention have been described above, it will be appreciated that the invention may be practiced otherwise than as described. For example, the invention may take the form of a computer program containing one or more sequences of machine-readable instructions describing a method as disclosed above, or a data storage medium (e.g. semiconductor memory, magnetic or optical disk) having such a computer program stored therein.

The descriptions above are intended to be illustrative, not limiting. Thus, it will be apparent to one skilled in the art that modifications may be made to the invention as described without departing from the scope of the claims set out below.

Other aspects of the invention are set out as in the following numbered clauses: 1. A lithographic system comprising: a first lithographic apparatus configured to project a patterned radiation beam onto a target portion of a substrate; and a second lithographic apparatus comprising: an illumination system configured to condition a radiation beam, an interferometric arrangement comprising a beam splitting arrangement configured to split the radiation beam into split beams and a recombination arrangement configured to recombine the split beams so as to produce an interference pattern at a field plane, a masking arrangement configured to selectively transmit a portion of the interference pattern, a substrate table configured to hold the substrate, and a projection system configured to project the selectively transmitted portion of the interference pattern onto a selected area of the target portion of the substrate. 2. The lithographic system of clause 1, wherein the substrate table is configured to move in correspondence with movement of the transmitted portions of the interference pattern over the field plane. 3. The lithographic system of clause 1, wherein the recombination arrangement is configured to recombine the split beams at a numerical aperture selected from the range of 0.7 to 0.95. 4. The lithographic system of clause 1, wherein the projection system is configured to project the selectively transmitted portion of the interference pattern onto a selected area of the target portion of the substrate at a numerical aperture selected from the range of 1.4 to 1.8. 5. The lithographic system of clause 1, wherein the projection system has a demagnification of minus 2. 6. The lithographic system of clause 1, wherein the illumination system is configured to produce a beam having a value of σ of not greater than 0.05. 7. An apparatus comprising: an illumination system configured to condition a radiation beam; an interferometric arrangement configured to split the radiation beam and to recombine the split beams so as to produce an interference pattern at a field plane; a masking arrangement configured to selectively transmit a portion of the interference pattern; a substrate table configured to hold the substrate; and a projection system configured to project the selectively transmitted portion of the interference pattern onto a target portion of the substrate. 8. The apparatus of clause 7, wherein the substrate table is configured to move in correspondence with movement of the transmitted portions of the interference pattern over the field plane. 9. An apparatus of clause 7, wherein the recombination arrangement is configured to recombine the split beams at a numerical aperture selected from the range of 0.7 to 0.95. 10. An apparatus of clause 7, wherein the projection system is configured to project the selectively transmitted portion of the interference pattern onto a selected area of the target portion of the substrate at a numerical aperture selected from the range of 1.4 to 1.8. 11. An apparatus of clause 7, wherein the projection system has a demagnification of minus two. 12. An apparatus of clause 7, wherein the illumination system is configured to produce a beam having a value of σ of not greater than 0.05. 13. A device manufacturing method comprising: using a first lithographic apparatus: to condition a radiation beam, to impart the radiation beam with a pattern in its cross-section to form a patterned radiation beam, and to project the patterned radiation beam onto a first target portion of the substrate; and using a second lithographic apparatus: to condition a radiation beam, to split the radiation beam and to recombine the split beams so as to produce an interference pattern at a field plane, to selectively transmit a portion of the interference pattern, and to project the selectively transmitted portion of the interference pattern onto a second target portion of the substrate. 14. A device manufactured using the system according to clause 1.

Claims (2)

1. Een lithografisch systeem omvattende: een eerste lithografisch apparaat ingericht om een stralingsbundel voorzien van een patroon in een dwarsdoorsnede van de stralingsbundel te projecteren op een trefdeel van een substraat; en een tweede lithografisch apparaat omvattende: een verlichtingssysteem ingericht om een stralingsbundel te conditioneren, en een interferometrische inrichting omavttende een bundel-splitsingsinrichting ingericht om de stralingsbundel te splitsen in deel-bundels, en een bundel-samenbrengingsinrichting ingericht om de deel-bundels samen te brengen ter generering van een interferentiepatroon in een veld vlak, een masker-inrichting ingericht om selectief een deel van het interferentiepatroon door te laten, een substraat-tafel ingericht om het substraat vast te houden, en een projectiesysteem ingericht om het selectief doorgelaten deel van het interferentiepatroon te projecteren op een geselecteerd deelgebied van het trefdeel van het substraat.

2. Een werkwijze voor het vervaardigen van een IC inrichting omvattende: het gebruik van een eerste lithografisch apparaat om een stralingsbundel te conditioneren en te voorzien van een patroon in een dwarsdoorsnede van de stralingsbundel, en om de van het patroon voorziende bundel te projecteren op een eerste trefdeel van een substraat; en het gebruik van een tweede lithografisch apparaat om een stralingsbundel te conditioneren en te splitsen in deel-bundels, en om vervolgens de deel-bundels samen te brengen ter generering van een interferentiepatroon in een veld vlak, en om selectief een deel van het interferentiepatroon door te laten, en om het selectief doorgelaten deel van het interferentiepatroon te projecteren op een tweede trefdeel van het substraat.