摘要:
A device is described for aligning a first object provided with a first alignment mark (P) with respect to a second object provided with a second alignment mark (M), which marks have a periodical structure and are imaged onto each other. By selecting beam portions from the radiation from the first alignment mark (P) with the aid of an order diaphragm (55'), which beam portions are deflected through larger angles, the sensitivity of the device to errors can be decreased. Such a device may be used to great advantage in a lithographic apparatus.
摘要:
A differential interferometer system for measuring the mutual positions and movements of a first object (WH) and a second object (MH). The system comprises a first interferometer unit (1, 2, 3, 4) having a first measuring reflector (RW) and a second interferometer unit (5, 6, 7, 8) having a second measuring reflector (RM). Since a measuring beam (b.sub.m) passes through both the first and the second interferometer unit and is reflected by both the first and the second measuring reflector, and since the measuring beam and the reference beam (b.sub.r) traverse the same path at least between the two interferometer units, accurate measurements can be preformed very rapidly. The interferometer system may be used to great advantage in a step-and-scan-lithographic projection apparatus.
摘要:
A method and apparatus for repetitively imaging a mask pattern (C) on a substrate (W) are described. The focusing of the projection lens system used for imaging and various other parameters of the apparatus and the projection lens system (PL), as well as illumination doses can be measured accurately and reliably, and measuring devices of the apparatus can be calibrated, by measuring an image of a new asymmetrical test mark formed in the photoresist on the substrate (W) by means of a projection beam (PB).
摘要:
A lithographic projection apparatus includes a radiation system for providing a projection beam of radiation having a wavelength &lgr;1 smaller than 50 nm; a support structure for supporting patterning structure, the patterning structure serving to pattern the projection beam according to a desired pattern; a substrate table for holding a substrate; and a projection system for projecting the patterned beam onto a target portion of the substrate. The apparatus further includes a radiation sensor which is located so as to be able to receive radiation out of the projection beam, said sensor comprising a radiation-sensitive material which converts incident radiation of wavelength &lgr;1 into secondary radiation; and sensing means capable of detecting said secondary radiation emerging from said layer.
摘要:
In an interferometer system, variations of the refractive index in the medium traversed by the measuring beam (123) can be detected by using two measuring beams (123, 125) having wavelengths which differ by a factor of three. For this choice of the wavelength ratio, the interference filters of the polarization elements, such as the beam splitter (127), the .lambda./4 plates (130, 131) and the antireflection coatings can be manufactured relatively easily, and the detection accuracy is increased.