Discharge source with gas curtain for protecting optics from particles
AssigneeEuv LLC
InventorsNeal R. Fornaciari, Michael P. Kanouff
Life of this patent
Estimating the term…
Abstract
A gas curtain device is employed to deflect debris that is generated by an extreme ultraviolet and soft x-ray radiation discharge source such as an electric discharge plasma source. The gas curtain device projects a stream of gas over the path of the radiation to deflect debris particles into a direction that is different from that of the path of the radiation. The gas curtain can be employed to prevent debris accumulation on the optics used in photolithography.
Claims24
A device that generates extreme ultraviolet and soft x-ray radiation that comprises:
- an EUV source that produces a beam of radiation along a path and that generates debris;
- and
- a gas curtain means for projecting a stream of gas at supersonic speeds over the path of radiation to deflect the debris into a direction that is different from that of the path of radiation.
A method of producing extreme ultra-violet and soft x-ray radiation that comprises the steps of:
- (i) providing an EUV source that produces a beam of radiation along a path and that generates debris;
- and
- (ii) projecting a stream of gas at supersonic speeds over the path of radiation to deflect the debris into a direction that is different from that of the path of radiation.
A method of producing extreme ultra-violet and soft x-ray radiation that comprises the steps of:
- (a) providing an electric discharge plasma source that comprises a:
- (i) body that defines a capillary bore that has a proximal end and a distal end;
- (ii) a first electrode defining a channel that has an inlet that is connected to a source of gas and an outlet end that is in communication with the distal end of the capillary bore;
- (iii) a second electrode positioned to receive radiation emitted from the proximal end of the capillary bore and having an opening through which radiation is emitted, wherein a majority of the radiation that is emitted travels through an annular shaped region;
- (iv) a source of electric potential that is connected across the first and second electrodes;
- (v) a source of second gas having a gas outlet that projects inert gas into the annular shaped region at supersonic speeds to cause debris particles, that are generated by the discharge plasma source, to be entrained in the inert gas;
- and
- (vi) a gas collecting member having a gas inlet through which inert gas containing entrained debris particles is recovered;
- (b) introducing second gas from the source of second gas into the channel of the first electrode and into the capillary bore;
- and
- (c) causing an electric discharge in the capillary bore sufficient to create a plasma within the capillary bore thereby producing radiation of a selected wavelength.
Dependencies are inferred from the claim text.