Systems and methods for concurrent measurements of interferometric and ellipsometric signals of multi-layer thin films
AssigneeNanoverse Technologies Ltd
InventorsMichael J. Darwin, Randy James
Life of this patent
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Abstract
A system may include a broadband light source emitting polarized light that is polarized to two orthogonal polarization states, multiple beam splitters for combining and splitting the polarization states, and interferometric cell for creation of interference patterns with respect to a sample surface, lenses of appropriate design that focus the polarized light at predefined locations, and sensors that analyze the polarized light as a function of angle and wavelength. The system may also include a controller configured to modulate the reference arm through operation of an optical chopper and allow for different data analysis modes to be used on the system produced data.
Claims9
An optical system, comprising:
- a broadband light source configured to emit broadband light;
- a polarizing device configured to receive the broadband light and generate a first beam of a first polarization and a second beam of a second polarization that is orthogonal to the first polarization;
- a polarizing beam splitter configured to combine and make coaxial the first and second beams;
- an interferometric cell configured to receive light from the first beam and second beam;
- a non-polarizing beam splitter of the interferometric cell configured to reflect and transmit the first and second beams and generate interference patterns due to the presence of a sample;
- a first lens, positioned between the polarizing device and the polarizing beam splitter;
- a second lens, positioned between the polarizing device and the polarizing beam splitter;
- a third lens, positioned between the second lens and the polarizing beam splitter;
- a fourth lens, positioned between the non-polarizing beam splitter and the sample;
- a fifth lens, positioned between the non-polarizing beam splitter and a flat mirror;
- a first mirror positioned between the polarizing device and the first lens;
- a second mirror positioned between the polarizing device and the second lens,
- wherein the first beam is reflected off of the first mirror and transmitted through the first lens which collimates the first beam, and wherein the second beam is reflected off of the second mirror, transmitted through the second lens, passed through an aperture, and transmitted through the third lens, where a design of the second lens and the third lens and a positioning of the aperture are appropriate for producing Koehler illumination from the second beam.
An optical system, comprising:
- a broadband light source configured to emit broadband light;
- a polarizing device configured to receive the broadband light and generate a first beam of a first polarization and a second beam of a second polarization that is orthogonal to the first polarization;
- an interferometric cell configured to receive incident light from the first beam and the second beam, and includes a polarizing beam splitter configured to combine and make coaxial the first beam and the second beam;
- a non-polarizing beam splitter of the interferometric cell configured to reflect and transmit the first and second beams and generate interference patterns due to the presence of a sample;
- a first lens, positioned between the polarizing device and the polarizing beam splitter;
- a second lens, positioned between the polarizing device and the polarizing beam splitter;
- a third lens, positioned between the second lens and the polarizing beam splitter;
- a fourth lens, positioned between the non-polarizing beam splitter and the sample;
- a fifth lens, positioned between the non-polarizing beam splitter and a flat mirror;
- a first mirror positioned between the polarizing device and the first lens;
- a second mirror positioned between the polarizing device and the second lens.
Dependencies are inferred from the claim text.