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US 2008/0259357 A1Published application
Optical metrology of single features
AssigneeTimbre Technologies, Inc.
InventorsJoerg BISCHOFF, Xinhui Niu, Junwei Bao
Life of this patent
Estimating the term…
Abstract
The profile of a single feature formed on a wafer can be determined by obtaining an optical signature of the single feature using a beam of light focused on the single feature. The obtained optical signature can then be compared to a set of simulated optical signatures, where each simulated optical signature corresponds to a hypothetical profile of the single feature and is modeled based on the hypothetical profile.
Claims20
A system for illuminating a single feature formed on a wafer, the system comprising:
- a source configured to generate a beam of light, the source having a first pupil stop with a first pupil hole that is de-centered with respect to the first pupil stop, wherein the first pupil stop has an effective numerical aperture greater than the wavelength of the light used divided by twice the distance between the single feature and an adjacent feature;
- a detector having a second pupil stop with a second pupil hole that is de-centered with respect to the second pupil stop, wherein the second pupil stop has an effective numerical aperture greater than the wavelength of the light used divided by twice the distance between the single feature and an adjacent feature;
- a focusing lens;
- and
- a beam splitter disposed adjacent to the focusing lens, wherein the beam of light generated by the source is focused on the single feature through the beam splitter and the focusing lens, and diffracted beams of light from the single feature are received in the detector through the focusing lens and the beam splitter.
2 more elements
A system for illuminating a single feature formed on a wafer, the system comprising:
- a source configured to generate a beam of light, the source having a first pupil stop with a first pupil hole that is de-centered with respect to the first pupil stop, wherein the first pupil stop has an effective numerical aperture greater than the wavelength of the light used divided by twice the distance between the single feature and an adjacent feature;
- a detector having a second pupil stop with a second pupil hole that is de-centered with respect to the second pupil stop, wherein the second pupil stop has an effective numerical aperture greater than the wavelength of the light used divided by twice the distance between the single feature and an adjacent feature;
- a focusing lens;
- a beam splitter disposed adjacent to the focusing lens, wherein the beam of light generated by the source is focused on the single feature through the beam splitter and the focusing lens, and diffracted beams of light from the single feature are received in the detector through the focusing lens and the beam splitter;
- and
- a processor connected to the detector configured to determine the profile of the single feature based on the diffracted beams of light received by the detector.
3 more elements
A method of illuminating a single feature formed on a wafer, the system comprising:
- generating a beam of light using a source, the source having a first pupil stop with a first pupil hole that is de-centered with respect to the first pupil stop, wherein the first pupil stop has an effective numerical aperture greater than the wavelength of the light used divided by twice the distance between the single feature and an adjacent feature;
- focusing the beam of light generated by the source on the single feature using a focusing lens;
- directing diffracted beams of light received from the single feature through the focusing lens to a detector using a beam splitter disposed adjacent to the focusing lens, the detector having a second pupil stop with a second pupil hole that is de-centered with respect to the second pupil stop, wherein the second pupil stop has an effective numerical aperture greater than the wavelength of the light used divided by twice the distance between the single feature and an adjacent feature;
- and
- determining the profile of the single feature based on the diffracted beams of light received by the detector.
2 more elements
Dependencies are inferred from the claim text.