| 摘要 |
A collector optical system for extreme ultraviolet (EUV) or X-ray applications, including lithography and imaging, for example at 13 5 nm, comprising a grazing incidence collector in combination with a laser produced plasma (LPP) source In one embodiment, one or more further optical elements act upon one or more laser beams used to generate the EUV or X-ray plasma source, whereby said laser beam(s) ?mpact(s) on the fuel target from a side thereof on which an intermediate focus is disposed Also disclosed is a collector for EUV and X-ray applications, in which radiation from a laser produced plasma source is reflected by the collector to an intermediate focus, the line joining the source and intermediate focus defining an optical axis, a first direction on the optical axis being defined from the source to the intermediate focus, characterised by the collector comprising one or more grazing incidence mirrors, and by the collector comprising one or more further optical elements for redirecting a received laser beam so as to be incident upon the source (a) in a second direction, opposite to said first direction, or (b) at an acute angle to said second direction The further optical elements may comprise plane or spherical mirrors and/or lenses, for example disposed on the optical axis Also disclosed is a collector for application at about 13 5 nm with Laser Produced Plasma sources, the collector comprising between 5 and 16 concentrically aligned mirrors, and preferably between 6 and 12 mirrors, that operate at grazing incidence such that the maximum grazing angle between the incident radiation and the reflective surface of the mirrors is about 30°, and more preferably about 25°, in order to allow a maximum collection angle from the source of about 40° to about 85°, and preferably about 45° to about 75° Also disclosed is an EUV lithography system comprising a radiation source, for example a LPP source, the collector, an optical condenser, and a reflective mask |
