US 2001/0055364 A1 · High-intensity sources of short-wavelength electromagnetic radiation for microlithography and other uses

Abstract

Sources are disclosed for producing short-wavelength electromagnetic radiation (EMR) such as extreme ultraviolet (“EUV” or “soft X-ray”) radiation useful in microlithography. The sources collect a greater amount of the EMR produced by a plasma than conventional sources and form the collected EMR into an illumination EMR flux having higher intensity than conventionally. The EMR flux desirably has a rotationally symmetrical intensity distribution. The plasma is produced by two electrodes contained in a vacuum chamber. A high-voltage pulsed power supply applies a plasma-creating potential across the electrodes. EMR produced by the plasma is collected, typically by a reflective element configured to form a collimated beam of EMR. The electrodes are configured and oriented such that, as the collimated beam passes by the electrodes, the electrodes exhibit minimal blocking of the EMR flux. The electrodes can include a center electrode and a surrounding hollow cylindrical electrode separated from the center electrode by an insulating member. The axis of rotational symmetry of the electrodes desirably is substantially parallel to the propagation axis of the EMR flux.

Claims28

Dependent claims

A device for generating a flux of electromagnetic radiation (EMR), comprising:

a vacuum chamber;
a first electrode located within the vacuum chamber, the first electrode having an axis of rotational symmetry, a distal end, and a proximal end;
a second electrode located within the vacuum chamber, the second electrode having a proximal end and being situated coaxially with but spaced apart from the first electrode, the first and second electrodes being connectable to a power supply configured to apply a high-voltage pulse across the first and second electrodes so as to generate an EMR-producing plasma adjacent the distal end of the first electrode;
an insulating member attached to the respective proximal ends of and extending between the first and second electrodes so as to support the first electrode relative to the second electrode;
and
an EMR-flux collimator situated in the vacuum chamber relative to the first and second electrodes such that EMR produced by the plasma is collected and collimated by the EMR-flux collimator to produce a collimated EMR flux, the EMR-flux collimator being situated and configured to direct the collimated EMR flux along a propagation axis, extending parallel to the axis of rotational symmetry of the first electrode, past the first and second electrodes.

3 more elements

Dependencies are inferred from the claim text.

High-intensity sources of short-wavelength electromagnetic radiation for microlithography and other uses

Life of this patent

High-intensity sources of short-wavelength electromagnetic radiation for microlithography and other uses

Life of this patent

Abstract

Claims28