Abstract: A scanning electron microscope and a method for evaluating a sample, the method may include (a) illuminating the sample with a primary electron beam, (b) directing secondary electrons emitted from the sample and propagated above a first scintillator, towards an upper portion of the first scintillator, wherein the first scintillator and a second scintillator are positioned between the sample and a column electrode of the column; wherein the first scintillator is positioned above the second scintillator; (c) detecting the secondary electrons by the first scintillator; (d) directing backscattered electrons emitted from the sample towards a lower portion of the second scintillator; and (e) detecting the backscattered electrons by the second scintillator.

Abstract: A method and a system for illuminating a substrate, the system may include an acousto-optic device (AOD); and an etendue expanding optical module. The AOD may include a surface having an illuminated region; wherein the illuminated region is configured to receive a collimated input beam while being fed with a control signal that causes the illuminated region to output illuminated region output beams that are collimated and exhibit deflection angles that scan, during a scan period, a deflection angular range. The etendue expanding optical module is configured to convert the illuminated region output beams to collimated output beams that impinge on an output aperture; wherein a collimated output beam has a width that exceeds a width of an illuminated region output beam; and wherein the etendue expanding optical module comprises a Dammann grating that is configured to output diffraction patterns, each diffraction pattern comprises diffraction orders that cover a continuous angular range.

Abstract: A method and a system for illuminating a substrate, the system may include an acousto-optic device (AOD); and an etendue expanding optical module. The AOD may include a surface having an illuminated region; wherein the illuminated region is configured to receive a collimated input beam while being fed with a control signal that causes the illuminated region to output illuminated region output beams that are collimated and exhibit deflection angles that scan, during a scan period, a deflection angular range. The etendue expanding optical module is configured to convert the illuminated region output beams to collimated output beams that impinge on an output aperture; wherein a collimated output beam has a width that exceeds a width of an illuminated region output beam; and wherein the etendue expanding optical module comprises a Dammann grating that is configured to output diffraction patterns, each diffraction pattern comprises diffraction orders that cover a continuous angular range.

Abstract: A scanning electron microscope and a method for evaluating a sample, the method may include (a) illuminating the sample with a primary electron beam, (b) directing secondary electrons emitted from the sample and propagated above a first scintillator, towards an upper portion of the first scintillator, wherein the first scintillator and a second scintillator are positioned between the sample and a column electrode of the column; wherein the first scintillator is positioned above the second scintillator; (c) detecting the secondary electrons by the first scintillator; (d) directing backscattered electrons emitted from the sample towards a lower portion of the second scintillator; and (e) detecting the backscattered electrons by the second scintillator.