1. A lithographic method comprising:
patterning a beam of radiation with a patterning device, the patterning device comprising at least two image patterning portions and at least two metrology mark patterning portions;
projecting at least two image portions of the patterned beam of radiation sequentially onto target portions of a substrate such that said projected image portions are substantially adjacent to each other on the substrate and collectively form a composite image on the substrate;
projecting a metrology mark onto the substrate outside of the area of the composite image at the same time as projecting each of at least two of the image portions; and
measuring the alignment of said metrology marks to determine the relative positions of the at least two image portions.
2. A lithographic method according to claim 1, wherein said projecting the metrology marks comprises projecting the metrology marks onto scribe lanes located on the substrate outside of the area of the composite image.
3. A lithographic method according to claim 1, wherein said measuring the alignment of said metrology marks comprises measuring a relative offset of the metrology marks.
4. A lithographic method according to claim 2, wherein said projecting the metrology marks comprises:
projecting a first metrology mark comprising an outline of a first shape onto the surface of the substrate; and
projecting a second metrology mark within the outline of the first shape, such that measuring the alignment of the metrology marks comprises measuring the offset of the second metrology mark from the center of the first metrology mark.
5. A lithographic method according to claim 1, wherein at least one of the metrology marks comprises diffraction gratings, and wherein said measuring the alignment of said metrology marks further comprises measuring interference between light reflected from the metrology marks.
6. A lithographic method according to claim 1, wherein the image portions are arranged to be substantially adjacent to each other on the substrate along a first axis.
7. A lithographic method according to claim 6, wherein the image portions are further arranged to be substantially adjacent to each other on the substrate along a second axis that is different from the first axis.
8. A lithographic method according to claim 1, wherein the image portions comprise image blocks and periphery blocks, and wherein the composite image comprises two or more image blocks surrounded by periphery blocks.
9. A lithographic method according to claim 8, further comprising screening off portions of the beam of radiation with a blading system such that projecting each image portion onto the substrate comprises projecting only those parts of the patterned projection beam relating to selected patterned portions onto the surface of the substrate.
10. A lithographic method according to claim 8, wherein each metrology mark patterning portion is in a fixed spatial relationship with a respective image block patterning portion or a respective periphery block patterning portion.
11. A lithographic method according to claim 8, wherein the composite image comprises a plurality of image blocks such that at least one image block is not adjacent to a periphery block.
12. A lithographic method according to claim 11, further comprising:
determining the relative positions of at least two of the image portions other than the at least one image block not adjacent to a periphery block; and
determining the probable position of the at least one image block not adjacent to a periphery block relative to at least one other image portion from said determined relative positions.
13. A lithographic method according to claim 1, further comprising calibrating the support structure for supporting the patterning device, the substrate table for holding the substrate andor the projection system using the determined alignment of the image portions.
14. A device manufactured according to the method of claim 1.
15. An image sensor manufactured according to the method of claim 1.
16. A lithographic method comprising:
patterning a beam of radiation with a patterning device;
projecting a plurality of image portions sequentially onto target portions of a substrate such that said projected image portions are substantially adjacent to each other on the substrate and collectively form a composite image on the substrate, the composite image comprising at least one image portion completely surrounded by other image portions;
determining the relative positions of at least two of the image portions, other than the image portion completely surrounded by other image portions; and
determining the probable position of the at least one image portion completely surrounded by other image portions, relative to at least one other image portion, from the determined relative positions.
17. A lithographic method according to claim 16, further comprising adjusting the position of the substrate andor adjusting a projection system used to project the patterned beam of radiation, to at least partially correct for a determined deviation of the position or shape of the surrounded image portion from an expected position or shape.
18. A patterning device for a lithographic apparatus, the patterning device comprising:
at least two image patterning regions; and
at least two metrology mark patterning regions, each metrology mark patterning region being in a fixed spatial relationship with a respective one of the image portion patterning regions,
wherein the image patterning regions are separated from one another.
19. A patterning device for a lithographic apparatus according to claim 18, wherein the image patterning regions comprise an image block patterning portion and one or more periphery block patterning portions, said metrology mark patterning portions being associated respectively with the image block patterning portion and each periphery block patterning portion, said patterning portions being adapted to impart the projection beam with a pattern in its cross section such that the composite image projected onto the substrate comprises two or more image blocks surrounded by periphery blocks.
20. A patterning device for a lithographic apparatus according to claim 19, wherein each image block patterning portion comprises a regular repeating pattern.
21. A patterning device for a lithographic apparatus according to claim 19, wherein each metrology mark patterning portion is in a fixed spatial relationship with a respective image block patterning portion or a respective periphery block patterning portion.
22. A patterning device for a lithographic apparatus according to claim 18, wherein the patterning device is a mask.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A control system for electric drives with a.c. motors, comprising means for determining the position of the rotor andor of the rotor flux or of the main magnetic field of electric drives or electric machines (ACEM) using an oscillating magnetic field (FH), starting from the phase difference between said oscillating magnetic field (FH) and the flux generated thereby, said phase difference being produced by the anisotropy, whether natural or induced, of the magnetic structure of the electric drive or electric machine (ACEM).
2. The control system of claim 1, wherein said oscillating magnetic field is at a fixed frequency and is generated by means of injection of a pre-set test signal.
3. The control system of claim 1, wherein said position of the rotor andor of the rotor flux or of the main magnetic field is determined by detecting the effects of anisotropy in different directions, according to a reference system synchronous with the stator of said electric drives or electric machines (ACEM).
4. The control system of claim 1, wherein said electric machines (ACEM) are of the synchronous type with reluctance or of the synchronous type with external permanent magnets andor of the isotropic or anisotropic synchronous type, or else of the asynchronous type.
5. The control system of claim 1, wherein, in synchronous electric machines (ACEM) supplied via an electronic circuit (PWM), said additional oscillating magnetic field (FH) is generated by adding to the voltage reference signals (VDS, VQS), synthesized by a current-control loop, an oscillating voltage component (VHD).
6. The control system of claim 5, wherein, in synchronous electric machines (ACEM) supplied via an electronic circuit (PWM), said additional oscillating magnetic field (FH) is generated by adding to the reference signals (IDSR, IQSR) of the current-control loop an oscillating current component (IHD).
7. The control system of claim 6, comprising: a plurality of blocks (ABCDQ, DQABC), designed to provide a transformation of reference axes from a fixed system to a rotating system and vice versa; and a series of regulation blocks (PI), which process a current-error signal and generate said voltage reference signals (VDS, VQS), which are then transformed into further references (VAS, VBS, VCS), via at least one of said blocks of transformation of the reference axes, and are sent to said electronic circuit (PWM), which supplies the a.c. electric machine (ACEM).
8. The control system of claim 2, comprising at least one first signal-filtering element, used for the current-control loop and designed to eliminate the components of the stator current (IS) generated by injection of said test signal, decoupling the current-control circuit from the system that carries out an estimation of the position (R) of the rotor.
9. The control system of claim 2, comprising at least one second element for signal bandpass filtering, which enables separation of the voltage and current harmonics generated by the injection of said test signal from the rest of the harmonic content of the voltage (VS) andor stator current (IS) in order to enable a correct processing thereof in a computing block, which determines the position (R) of the rotor.
10. A control method which can be implemented on a system of claim 1, comprising at least one of the following steps, taken individually or in combination:
superposition of an oscillating single-phase voltage component (VHD) on the three-phase stator voltage of an electric machine (ACEM), in such a way as to generate an oscillating magnetic field (FH) rotating at the speed of the rotor flux, which in turn generates an oscillating flux rotating at the speed of the rotor flux and out of phase with respect to said oscillating magnetic field (FH) by an angle that is a function of the relative position between said single-phase voltage component (VHD) and the magnetic-induction flux of the rotor; and
injection of a single-phase oscillating current component (IHD) to the three-phase stator current of an electric machine (ACEM), in such a way as to generate an oscillating magnetic field (FH) rotating at the speed of the rotor flux, which in turn generates an oscillating flux rotating at the speed of the rotor flux and out of phase with respect to said oscillating magnetic field (FH) by an angle that is a function of the relative position between said single-phase current component (IHD) and the magnetic-induction flux of the rotor.