Methods and systems for performing single wavelength ellipsometry (SWE) measurements with reduced measurement spot size are presented herein. In one aspect, a pupil stop is located at or near a pupil plane in the collection optical path to reduce sensitivity to target edge diffraction effects. In another aspect, a field stop is located at or near an image plane conjugate to the wafer plane in the collection optical path to reduce sensitivity to undesired optical-structural interactions. In another aspect, a linear polarizer acting on the input beam of the SWE system includes a thin, nanoparticle based polarizer element. The nanoparticle based polarizer element improves illumination beam quality and reduces astigmatism on the wafer plane. The pupil and field stops filter out unwanted light rays before reaching the detector. As a result, measurement spot size is reduced and tool-to-tool matching performance for small measurement targets is greatly enhanced.

The present disclosure generally pertains to a polarization imaging system having: an imaging portion having a color channel element of a first color type and a color channel element of a second color type; and a light polarization portion configured to: provide a first light polarization of a first polarization type for the first color type and a second light polarization of the first polarization type for the second color type; and convert a second polarization type into the first polarization type, whereby the second polarization type is detectable in the imaging portion.

A measurement device includes a light source configured to emit a fundamental wave that is a femtosecond pulsed laser beam, a second harmonic generator configured to convert a portion of the fundamental wave into a first-second harmonic, a birefringent crystal configured to split an angle for the first-second harmonic, a wavelength selection element configured to block the fundamental wave and transmit therethrough the first-second harmonic and a second-second harmonic, a polarizer configured to polarize the first-second harmonic and the second-second harmonic to approximately same polarizations, and an image detector.

An optical measurement apparatus includes a light source unit generating and outputting light, a polarized light generating unit generating polarized light from the light, an optical system generating a pupil image of a measurement target, using the polarized light, a self-interference generating unit generating multiple beams that are split from the pupil image, and a detecting unit detecting a self-interference image generated by interference of the multiple beams with each other.

A method for measuring a multilayered substrate, particularly with at least one structure with critical dimensions, the method including the steps of (a) producing the substrate with a plurality of layers, particularly with a structure, wherein the dimensions of the layers and in particular the structures are known, (b) measuring the substrate using at least one measuring technology, (c) creating a simulation of the substrate using the measurement results from the measurement of the substrate, (d) comparing the measurement results with simulation results from the simulation of the substrate, and (e1) optimizing the simulation and renewed creation of a simulation of the substrate using the measurement results from the measurement of the substrate, in the event that there is a deviation of the measurement results from the simulation results, or (e2) calculating parameters of further substrates, in the event that the measurement results correspond to the simulation results.

A method for measuring a multilayered substrate, particularly with at least one structure with critical dimensions, the method including the steps of (a) producing the substrate with a plurality of layers, particularly with a structure, wherein the dimensions of the layers and in particular the structures are known, (b) measuring the substrate using at least one measuring technology, (c) creating a simulation of the substrate using the measurement results from the measurement of the substrate, (d) comparing the measurement results with simulation results from the simulation of the substrate, and (e1) optimizing the simulation and renewed creation of a simulation of the substrate using the measurement results from the measurement of the substrate, in the event that there is a deviation of the measurement results from the simulation results, or (e2) calculating parameters of further substrates, in the event that the measurement results correspond to the simulation results.