Back to results
US 6,285,743 B1Granted
Method and apparatus for soft X-ray generation
AssigneeNikon Corporation
InventorsHiroyuki Kondo, Noriaki Kandaka
Life of this patent
Estimating the term…
Abstract
A soft X-ray source includes a mirror having a focal point, the mirror being one of parabolic and ellipsoidal, a nozzle delivering a target material to a plasma generation point substantially coincident with the focal point, and a laser source delivering a pulsed laser beam to the plasma generation point, wherein a plasma is generated at the plasma generation point upon irradiation by the pulsed laser beam, the plasma emitting soft X-rays that are formed into beams by the mirror, the beams being parallel if the mirror is parabolic and converging if the mirror is ellipsoidal.
Claims33
A soft X-ray source comprising:
- a mirror having a focal point, the mirror being parabolic or ellipsoidal;
- a nozzle delivering a target material to a plasma generation point substantially coincident with the focal point;
- and
- a laser source delivering a pulsed laser beam to the plasma generation point,
- wherein a plasma is generated at the plasma generation point upon irradiation by the pulsed laser beam, the plasma emitting soft X-rays that are formed into X-ray beams by the mirror,
- wherein the X-ray beams are parallel if reflected from the parabolic mirror and converging if reflected from the ellipsoidal mirror, and
- wherein one of an axis of the nozzle and an axis of the pulsed laser beam is coaxial with an axis of the mirror.
4 more elements
A method of generating soft X-rays comprising the steps of:
- ejecting a target material from a nozzle towards a plasma generation point;
- irradiating the target material with a pulsed laser beam;
- and
- forming soft X-ray beams by reflecting soft X-rays emitted by the plasma from a mirror, the mirror being parabolic or ellipsoidal, the soft X-ray beams being parallel or converging,
- wherein the pulsed laser beam is directed towards substantially a focal point of the mirror, the focal point being substantially coincident with the plasma generation point, and
- wherein one of an axis of the nozzle and an axis of the pulsed laser beam is coaxial with an axis of the mirror.
3 more elements
An apparatus for generating soft X-rays comprising:
- a nozzle ejecting a target material towards a plasma generation point;
- a mirror having a focal point that substantially corresponds to the plasma generation point, the mirror being parabolic or ellipsoidal;
- and
- a laser source delivering at least two pulsed laser beams to the plasma generation point,
- wherein a plasma is generated at the plasma generation point in response to irradiation by the two pulsed laser beams, and
- wherein the plasma emits the soft X-rays, the soft X-rays being reflected into parallel or converging X-ray beams by the mirror, and
- wherein one of an axis of the nozzle and an axis of the pulsed laser beam is coaxial with an axis of the mirror.
4 more elements
A method of generating soft X-rays comprising the steps of:
- ejecting a target material towards a plasma generation point from a nozzle;
- irradiating the target material at the plasma generation point with at least two pulsed laser beams so as to form a plasma;
- and
- reflecting soft X-rays emitted by the plasma from a mirror to form beams, the mirror being parabolic or ellipsoidal,
- wherein the beams are parallel if reflected from the parabolic mirror and converging if reflected from the ellipsoidal mirror,
- wherein a focal point of the mirror is substantially coincident with the plasma generation point, and
- wherein one of an axis of the nozzle and an axis of the pulsed laser beam is coaxial with an axis of the mirror.
4 more elements
An electromagnetic wave source comprising:
- a low pressure vessel;
- a nozzle in the low pressure vessel, the nozzle ejecting a target material towards a plasma generation point;
- a mirror having a focus corresponding to the plasma generation point, the mirror being parabolic or ellipsoidal;
- and
- a laser irradiating the target material at the plasma generation point to convert a portion of the target material into a plasma,
- wherein electromagnetic energy emitted by the plasma is reflected from the mirror to form beams,
- wherein the beams are parallel if reflected from the parabolic mirror and converging if reflected from the ellipsoidal mirror.
4 more elements
An exposure apparatus comprising:
- a source of electromagnetic waves in a wavelength range between 0.1 nm to 300 nm;
- a source of target material, the target material being one of a liquid, liquid droplets, fine particles, gas and clusters;
- an irradiation source for irradiating the target material and converting the target material into a plasma that emits radiation in the wavelength range between 0.1 nm to 300 nm,
- wherein the source of electromagnetic waves includes an optical element for shaping the radiation into the electromagnetic waves,
- wherein a reflective surface of the optical element is substantially axially symmetrical,
- wherein the irradiation source irradiates the target material from a direction of the optical element,
- wherein the source of the target material does not block a path of the electromagnetic waves, and
- wherein the electromagnetic waves are parallel if reflected from the parabolic mirror and converging if reflected from the ellipsoidal mirror.
5 more elements
Dependencies are inferred from the claim text.