Optical system and method for measuring parameters of patterned structures in micro-electronic devices

• Main Authors: Dotan, Elad, Gov, Shahar, Grossman, Danny, Engel, Guy, Vanhotsker, Moshe
• Format: Patent
• Language: English
• Published: 29.11.2022
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; PHYSICS; SEMICONDUCTOR DEVICES; TESTING

An optical system and method are presented for use in measurements on an upper surface of a layered sample when located in a measurement plane. The optical system is configured as a normal-incidence system having an illumination channel and a collection channel, and comprises an objective lens unit and a light propagation affecting device. The objective lens unit is accommodated in the illumination and collection channels, thereby defining a common optical path for propagation of illuminating light from the illumination channel toward an illuminating region in the measurement plane and for propagation of light returned from measurement plane to the collection channel. The light propagation affecting device comprises an apertured structure located in at least one of the illumination and collection channels, and configured to provide angular obscuration of light propagation path for blocking angular segments associated with light propagation from regions outside the illuminated region.