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.
Claims23
1-55. (canceled)
A system for illuminating a single feature formed on a wafer, the system comprising:
- a source with a focusing lens to focus a beam of light onto the single feature, the focusing lens having a 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 configured to detect beams of light diffracted from the single feature;
- and
- a processor connected to the detector configured to determine the profile of the single feature based on the beams of light detected by the detector.
A system for illuminating a single feature formed on a wafer, the system comprising:
- a source with a focusing lens to focus a beam of light onto the single feature, the focusing lens having a 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 with a focusing lens to focus beams of light diffracted from the single feature;
- and
- a processor connected to the detector configured to determine the profile of the single feature based on the beams of light detected by the detector.
A system for illuminating a single feature formed on a wafer, the system comprising:
- a source configured to generate a beam of light to be focused onto the single feature;
- a detector configured to detect beams of light diffracted from the single feature;
- a single focusing lens shared by the source and the detector, the focusing lens having a numerical aperture greater than the wavelength of the light used divided by twice the distance between the single feature and an adjacent feature;
- a beam splitter disposed adjacent to the single focusing lens, wherein the beam of light generated in the source is focused on the single feature through the beam splitter and the focusing lens, and the diffracted beams of light are detected 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 beams of light detected by the detector.
The system of claim 71, wherein the source includes a pupil stop configured to generate oblique incidence, and the detector includes a pupil stop. claim 73. The system of claim 72, wherein the pupil stop of the source and the pupil stop of the detector are configured to synchronously shift from an initial incidence angle to a final incidence angle.
A method of illuminating a single feature formed on a wafer, the method comprising:
- generating a beam of light using a source;
- focusing the generated beam of light using a focusing lens having a numerical aperture greater than the wavelength of the light used divided by twice the distance between the single feature and an adjacent feature;
- detecting beams of light diffracted from the single feature using a detector;
- and
- determining the profile of the single feature based on the beams of light detected by the detector using a processor connected to the detector.
Dependencies are inferred from the claim text.