Patent ID: 7399981

Claim:
A device for generating light in the extreme ultraviolet (EUV), the device comprising: a) a plurality of power laser sources for emitting a plurality of laser beams; b) a focusing device for focusing the laser beams to produce focused laser beams; c) a device for creating an evacuated space with pressure lower than 1 Pa at least in the zone where said focused laser beams are focused; d) a device for creating a dense target in said space where said focused laser beams are focused, the dense target being suitable for interacting with said focused laser beams to emit a plasma possessing at least one emission line in the extreme ultraviolet; e) a receiver device for receiving the target after it has interacted with said focused laser beams; and f) at least one first device for collecting the EUV radiation emitted by the target; the device being characterized in that it has a mean collection axis for EUV radiation perpendicular to the axis defined by the essentially linear dense target; in that the focusing device for focusing the laser beams on the target is arranged in such a manner that the laser beams are focused laterally on the target while being situated in a common half-space relative to the target and while being inclined at a predetermined angle (β) lying in the range about 60° to about 90° relative to said mean collection axis; in that said first collector device is disposed symmetrically about said mean collection axis in the half-space containing the laser beams focused on the target and within a conical space centered on the mean collection axis with its vertex situated on the target and a half-angle (α) at the vertex less than the angle of inclination (β) of the focused laser beams relative to the mean collection axis and in that the number of focused laser beams included therein lies in the range 3 to 20.