Abstract:
Disclosed are systems and methods for object inspection, in particular for inspection of reticles used in a lithography process. The method includes interferometrically combining a reference radiation beam with a probe radiation beam, and storing their complex field images. The complex field image of one object is then compared with that of a reference object to determine the differences. The systems and methods have particular utility in the inspection of a reticle for defects.
Abstract:
Systems and methods are described for recording multiple spatially-heterodyned direct to digital holograms in one digital image. A method includes digitally recording, at a first reference beam-object beam angle, a first spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; Fourier analyzing the recorded first spatially-heterodyned hologram by shifting a first original origin of the recorded first spatially-heterodyned hologram to sit on top of a first spatial-heterodyne carrier frequency defined by the first reference beam-object beam angle; digitally recording, at a second reference beam-object beam angle, a second spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; Fourier analyzing the recorded second spatially-heterodyned hologram by shifting a second original origin of the recorded second spatially-heterodyned hologram to sit on top of a second spatial-heterodyne carrier frequency defined by the second reference beam-object beam angle; applying a first digital filter to cut off signals around the first original origin and define a first result; performing a first inverse Fourier transform on the first result; applying a second digital filter to cut off signals around the second original origin and define a second result; and performing a second inverse Fourier transform on the second result, wherein the first reference beam-object beam angle is not equal to the second reference beam-object beam angle and a single digital image includes both the first spatially-heterodyned hologram and the second spatially-heterodyned hologram.
Abstract:
Systems and methods are described for spatial-heterodyne interferometry for reflection and transmission (SHIRT) measurements. A method includes digitally recording a first spatiallyheterodyned hologram using a first reference beam and a first object beam; digitally recording a second spatially-heterodyned hologram using a second reference beam and a second object beam; Fourier analyzing the digitally recorded first spatially-heterodyned hologram to define a first analyzed image; Fourier analyzing the digitally recorded second spatially-heterodyned hologram to define a second analyzed image; digitally filtering the first analyzed image to define a first result; and digitally filtering the second analyzed image to define a second result; performing a first inverse Fourier transform on the first result, and performing a second inverse Fourier transform on the second result. The first object beam is transmitted through an object (940, 1045) that is at least partially translucent, and the second object beam is reflected from the object.
Abstract:
In digital holographic imaging systems, streamed holograms are compared on a pixel-by-pixel basis for defect detection after hologram generation. An automated image matching, registration and comparison method with feedback confidence allows for runtime wafer inspection, scene matching refinement, rotational wafer alignment and the registration and comparison of difference images.
Abstract:
Systems and methods are described for rapid acquisition of fused off-axis illumination direct-to-digital holography. A method of recording a plurality of off-axis illuminated spatially heterodyne holograms, each of the off-axis illuminated spatially heterodyne holograms including spatially heterodyne fringes for Fourier analysis, includes digitally recording, with a first illumination source of an interferometer, a first off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis; and digitally recording, with a second illumination source of the interferometer, a second off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis.
Abstract:
A method for patterning a layer on a substrate can include projecting coherent radiation toward a reflector surface so that the coherent radiation is reflected off the reflector surface to provide a holographic projection of a desired image wherein the reflector surface includes information that corresponds to an inverse of the holographic projection of the desired image. The substrate including the layer can be maintained in the path of the reflected radiation so that the holographic projection is projected onto the layer. Related systems are also discussed.
Abstract:
Interferometric system with variable optics for non-coherent source of radiation and method of interferometric system alignment The invention relates to the interferometric system for creation of hologram with spatial carrier frequency comprising a source of radiation (1) with low coherence, behind which a field plane (2) optically conjugated with an output image plane (10) is arranged, a beam splitter (4) for splitting the beam of radiation into two separate branches of interferometer, an object branch with plurality of optical elements, a reference branch with plurality of optical elements, a diffraction grating (7), an extender (12), a transmission system of reflectors and a detector arranged in the output image plane (10), wherein the plurality of optical elements in the object branch includes a objective lens (5.12), wherein the objective lens used in the reference branch is not identical with the one used in the object branch, which means a significant financial saving. The system comprises object and reference input imaging systems (5.1) and (5.2) and object and reference output imaging systems (8.1) and (8.2) wherein one of them includes an optical element with variable focal length.
Abstract:
Microscope (2) comprising a coherent light source (4) producing a coherent light beam (7), a light beam guide system (6) comprising a beam splitter (14) configured to split the coherent light beam (7) into a reference beam (7a) and a sample illumination beam (7b), a sample holder (18) configured to hold a sample (1) to be observed, a sample illumination device (28) configured to direct the sample illumination beam (7b) through the sample and into a microscope objective (37), a beam reuniter (16) configured to reunite the reference beam and sample illumination beam after passage of the sample illumination beam through the sample to be observed, and a light sensing system (8) configured to capture at least phase and intensity values of the coherent light beam downstream of the beam reuniter.
Abstract:
Systems and methods are described for faster processing of multiple spatially-heterodyned direct to digital holograms. A method includes of obtaining multiple spatially-heterodyned holograms, includes: digitally recording a first spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; digitally recording a second spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; Fourier analyzing the recorded first spatially-heterodyned hologram by shifting a first original origin of the recorded first spatially-heterodyned hologram including spatial heterodyne fringes in Fourier space to sit on top of a spatial-heterodyne carrier frequency defined as a first angle between a first reference beam and a first object beam; applying a first digital filter to cut off signals around the first original origin and performing an inverse Fourier transform on the result; Fourier analyzing the recorded second spatially-heterodyned hologram by shifting a second original origin of the recorded second spatially-heterodyned hologram including spatial heterodyne fringes in Fourier space to sit on top of a spatial-heterodyne carrier frequency defined as a second angle between a second reference beam and a second object beam; and applying a second digital filter to cut off signals around the second original origin and performing an inverse Fourier transform on the result, wherein digitally recording the first spatially-heterodyned hologram is completed before digitally recording the second spatially-heterodyned hologram and a single digital image includes both the first spatially-heterodyned hologram and the second spatially-heterodyned hologram.