Method and apparatus for light span microscopic dark-field display of objects
AssigneeCarl-Zeiss-Stiftung
InventorsAugustin Siegel, Peter Seidel
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Abstract
A method used for the inspection of semiconductor structures under a light scan microscope which scans the surface of the wafer or other specimen (12) with a beam of light which is focused in spot form by the objective (18). In order to produce a dark-field image in which the linear semiconductor structures of the wafer are suppressed and only defects and particles of dirt are visible, the signals of four detectors (10a-10d) arranged outside the illuminating aperture of the objective within the channel of the dark-field ring condenser (6) are subjected to a logical "and" operation.
Claims11
A method for light scan microscopic dark-field display of objects which comprises providing a light scan microscope having an optical system including a member chosen from the group consisting of an objective and a condenser, said microscope having an illuminating optical system which has an aperture, arranging a plurality of at least three detectors in a circle around said member and outside said aperture of said illuminating optical system, and subjecting output signals from said detectors to a logical "and" operation in such manner that a dark-field image display (y) takes place only when all detectors simultaneously give an output signal of comparable size.
Apparatus for light scan microscopic dark-field display of objects, said apparatus comprising a light scan microscope having an optical system including a member chosen from the group consisting of an objective and a condenser, a plurality of at least three detectors arranged in an annular dark-field channel surrounding said member, said detectors providing output signals responsive to light reaching the respective detectors, and electronic circuit means for processing said output signals from said detectors.
Dependencies are inferred from the claim text.