Abstract: An automated photomask inspection apparatus including an XY state (12) for transporting a substrate (14) under test in a serpentine path in an XY plane, an optical system (16) comprising a laser (30), a transmission light detector (34), a reflected light detector (36), optical elements defining reference beam paths and illuminating beam paths between the laser, the substrate and the detectors and an acousto-optical beam scanner (40, 42) for reciprocatingly scanning the illuminating and reference beams relative to the substrate surface, and an electronic control, analysis and display system for controlling the operation of the stage and optical system and for interpreting and storing the signals output by the detectors. The apparatus can operate in a die-to-die comparison mode or a die-to-database mode.

Abstract: An automated photomask inspection apparatus including an XY state (12) for transporting a substrate (14) under test in a serpentine path in an XY plane, an optical system (16) comprising a laser (30), a transmission light detector (34), a reflected light detector (36), optical elements defining reference beam paths and illuminating beam paths between the laser, the substrate and the detectors and an acousto-optical beam scanner (40, 42) for reciprocatingly scanning the illuminating and reference beams relative to the substrate surface, and an electronic control, analysis and display system for controlling the operation of the stage and optical system and for interpreting and storing the signals output by the detectors. The apparatus can operate in a die-to-die comparison mode or a die-to-database mode.

Abstract: The broadband brightfield/darkfield wafer inspection system provided receives broadband brightfield illumination information via a defect detector, which signals for initiation of darkfield illumination. The defect detector forms a two dimensional histogram of the defect data and a dual mode defect decision algorithm and post processor assess defects. Darkfield radiation is provided by two adjustable height laser beams which illuminate the surface of the wafer from approximately 6 to 39 degrees. Each laser is oriented at an azimuth angle 45 degrees from the orientation of the Manhattan geometry on the wafer, and 90 degrees in azimuth from one another. Vertical angular adjustability is provided by modifying cylindrical lens position to compensate for angular mirror change by translating an adjustable mirror, positioning the illumination spot into the sensor field of view, rotating and subsequently moving the cylindrical lens.

Abstract: An automated photomask inspection apparatus including an XY state (12) for transporting a substrate (14) under test in a serpentine path in an XY plane, an optical system (16) comprising a laser (30), a transmission light detector (34), a reflected light detector (36), optical elements defining reference beam paths and illuminating beam paths between the laser, the substrate and the detectors and an acousto-optical beam scanner (40, 42) for reciprocatingly scanning the illuminating and reference beams relative to the substrate surface, and an electronic control, analysis and display system for controlling the operation of the stage and optical system and for interpreting and storing the signals output by the detectors. The apparatus can operate in a die-to-die comparison mode or a die-to-database mode.

Abstract: A method and apparatus for inspecting patterned transmissive substrates, such as photomasks, for unwanted particles and features occurring on the transmissive, opaque portions and at the transition regions of the opaque and transmissive portions of the substrate. A transmissive substrate is illuminated by a laser through an optical system comprised of a laser scanning system, individual transmitted and reflected light collection optics and detectors collect and generate signals representative of the light transmitted and reflected by the substrate as the substrate is scanned repeatedly in one axis in a serpentine pattern by a laser beam which is focused on the patterned substrate surface. The defect identification of the substrate is performed using only those transmitted and reflected light signals, and other signals derived from them, such as the second derivative of each of them.

Abstract: An automated photomask inspection apparatus including an XY state (12) for transporting a substrate (14) under test in a serpentine path in an XY plane, an optical system (16) comprising a laser (30), a transmission light detector (34), a reflected light detector (36), optical elements defining reference beam paths and illuminating beam paths between the laser, the substrate and the detectors and an acousto-optical beam scanner (40, 42) for reciprocatingly scanning the illuminating and reference beams relative to the substrate surface, and an electronic control, analysis and display system for controlling the operation of the stage and optical system and for interpreting and storing the signals output by the detectors. The apparatus can operate in a die-to-die comparison mode or a die-to-database mode.

Abstract: A method and apparatus for inspecting patterned transmissive substrates, such as photomasks, for unwanted particles and features occurring on the transmissive, opaque portions and at the transition regions of the opaque and transmissive portions of the substrate. A transmissive substrate is illuminated by a laser through an optical system comprised of a laser scanning system, individual transmitted and reflected light collection optics and detectors collect and generate signals representative of the light transmitted and reflected by the substrate as the substrate is scanned repeatedly in one axis in a serpentine pattern by a laser beam which is focused on the patterned substrate surface. The defect identification of the substrate is performed using only those transmitted and reflected light signals, and other signals derived from them, such as the second derivative of each of them.