High-luminosity EUV-source devices for use in extreme ultraviolet (soft X-ray) lithography systems and other EUV optical systems

In combination:

• an EUV-optical system;
• and
• an EUV-source device that directs an illumination beam to the EUV-optical system, the EUV-source device comprising (a) multiple individual EUV-light sources each providing a respective point-light source of EUV radiation propagating as a respective beam from each point-light source;
• (b) a reflective focusing-optical system situated downstream of the EUV-light sources, the focusing-optical system being configured to focus the beams from the point-light sources at a focus point;
• (c) a variable-angle mirror situated downstream of the focusing-optical system and configured to reflect light of the respective beams from the point-light sources that has been reflected by the focusing-optical system;
• and (d) a mirror-tilting mechanism coupled to the variable-angle mirror and configured, when actuated, to tilt the mirror by a respective angle corresponding to the particular beam from one of the point-light sources that currently is incident on the variable-angle mirror, thereby producing a composite illumination beam of EUV light propagating in a constant direction from the variable-angle mirror.

An EUV-microlithography system, comprising:

• an illumination-optical system situated and configured to direct an EUV illumination beam to a pattern-defining reticle;
• an EUV-source device that directs the illumination beam to the illumination-optical system, the EUV-source device comprising (a) multiple individual EUV-light sources each providing a respective point-light source of EUV radiation propagating as a respective beam from each point-light source;
• (b) a reflective focusing-optical system situated downstream of the EUV-light sources, the focusing-optical system being configured to focus the beams from the point-light sources at a focus point;
• (c) a variable-angle mirror situated downstream of the focusing-optical system and configured to reflect light of the respective beams from the point-light sources that has been reflected by the focusing-optical system;
• and (d) a mirror-tilting mechanism coupled to the variable-angle mirror and configured, when actuated, to tilt the mirror by a respective angle corresponding to the particular beam from one of the point-light sources that currently is incident on the variable-angle mirror, thereby producing a composite illumination beam of EUV light propagating in a constant direction from the variable-angle mirror;
• and
• a projection-optical system situated downstream of the illumination-optical system, the projection-optical system being configured to form an image, of a region of the reticle illuminated by the illumination beam, on a corresponding region of a substrate.

A method for producing a beam of EUV radiation, the method comprising:

• producing respective beams of EUV light from multiple selectively activatable EUV-light sources, the respective beams having respective principal rays;
• directing the respective beams in a manner causing the respective principal rays to intersect each other at an intersection point and focusing each of the beams at a focus point;
• and
• at the intersection point, reflecting light of the respective beams from the focusing-optical system to form a composite beam propagating in a constant direction.

A method for reducing the etendue of an EUV-source device that forms an illumination beam from multiple EUV-light sources, the method comprising:

• producing respective beams of EUV light from multiple selectively activatable EUV-light sources, the respective beams having respective principal rays;
• directing the respective beams in a manner causing the respective principal rays to intersect each other at an intersection point and focusing each of the beams at a focus point;
• and
• at the intersection point, reflecting light of the respective beams from the focusing-optical system to form a composite illumination beam propagating in a constant direction.