Back to results
US 8,013,999 B2Granted
Beam characterization monitor for sensing pointing or angle of an optical beam
AssigneeASML Holding N.V.
InventorsMatthew E. Hansen, Ronald A. Wilklow
Life of this patent
Estimating the term…
Abstract
The divergence of an optical beam is determined. An optic is configured to provide internal reflection of at least a part of a beam of radiation scanned over varying angles of incidence on the optic. The optic has a film configured to provide a surface plasmon resonance (SPR) effect. A detector is arranged relative to the optic and configured to electronically detect radiation reflected from the optic. The divergence angle of the beam of radiation is calculated based on a change in reflectance relative to angle of incidence.
Claims25
A method, comprising:
- illuminating, with a radiation beam, an optic comprising an internal surface and a transmissive material configured to allow surface plasmon resonance (SPR) assisted total internal reflection (TIR) of the radiation beam,
- wherein the radiation beam reflects from the internal surface of the optic at an incident angle or a range of angles comprising a divergence angle;
- electronically measuring a percentage of radiation reflected from the optic;
- and
- determining at least one of the incident angle and the divergence angle of the radiation beam based on a known angular dependence of the percentage of radiation reflected from the optic.
2 more elements
A sensor, comprising:
- an optic comprising an internal surface and a transmissive material configured to allow surface plasmon resonance (SPR) assisted total internal reflection (TIR) of an incident radiation beam,
- wherein the optic is configured so that the radiation beam reflects from the internal surface of the optic at an incident angle, or a range of angles comprising a divergence angle;
- and
- a detector configured to electronically measure a percentage of radiation reflected from the optic, and wherein the detector is further configured to determine at least one of the incident angle and the divergence angle of the radiation beam based on a known angular dependence of the percentage of radiation reflected from the optic.
1 more element
A lithographic apparatus, comprising:
- an illumination system configured to condition a radiation beam and comprising a sensor configured to measure an incident angle or divergence angle of the radiation beam, the sensor including:
- an optic comprising an internal surface and a transmissive material configured to allow surface plasmon resonance (SPR) assisted total internal reflection (TIR) of the radiation beam,
- wherein the optic is configured so that the radiation beam reflects from the internal surface of the optic at an incident angle, or a range of angles comprising, a divergence angle;
- and
- a detector configured to electronically measure a percentage of radiation reflected from the optic, and wherein the detector is further configured to determine at least one of the incident angle and the divergence angle of the radiation beam based on a known angular dependence of the percentage of radiation reflected from the optic;
- an array of individually controllable elements configured to modulate the beam of radiation;
- and
- a projection system configured to project the modulated radiation beam onto a target portion of a photosensitive substrate.
5 more elements
Dependencies are inferred from the claim text.