METHOD OF GENERATING EUV RADIATION METHOD OF MANUFACTURING A DEVICE BY MEANS OF SAID RADIATION EUV RADIATION SOURCE UNIT AND LITHOGRAPHIC PROJECTION APPARATUS PROVIDED WITH SUCH A RADIATION SOURCE UNIT

摘要

The present invention relates to a method of producing EUV radiation, comprising the steps of producing a flow 35 of a liquid droplet 39, injecting the flow into a source space 33 connected to a vacuum pump 34, , And successively irradiating the individual droplets 39 with a strong, pulsed laser beam 41 focused on the droplet to produce a plasma 47 that emits EUV radiation. To prevent liquid vapor from destroying the vacuum in the source space 33 and to ensure a continuous flow of the EUV radiation, the flow 35 is conducted through additional vacuum spaces 53, 56, 63 connected in series with the source space . An EUV radiation source unit implementing this method and the application of this method to apparatus manufacturing and lithographic projection apparatus such as IC devices are also described.