Qc Optics, Inc.

George S Quackenbos

Sergey V Broude

Eric T Chase

Jay L Ormsby

Koichi Nishine

Carl E Johnson

Abdu Bou Dour

An optical inspection system and method for detecting flaws on a diffractive surface such as a reticle or wafer, includes illuminating a surface to be inspected to generate a first scattered energy angular distribution in response to a flaw on the surface and a second scattered energy angular distribution in response to an unflawed surface; the first and second energy distributions are sensed and the minimum energy detection energy level is established; determining whether the minimum detected energy level is in a first or second predetermined energy range and indicating that no flaw is present when the minimum detected energy level is in the first range and a flaw is present when the minimum detected energy level is in the second range.

Inspection apparatus and method for detecting flaws on a diffractive

A surface inspection defect detection and confirmation technique in which a beam of radiation is directed at the surface to be inspected; the radiation scattered from the surface is separately sensed in the near-specular region indicative of a pit and in the far-specular region indicative of a flaw, the near-specular region signal and far-specular region signal are normalized, the near-specular component is discriminated, and the flaw signal is indicated as being a defect and not contamination when there is coincidence between the pit signal and flaw signal.

Surface defect detection and confirmation system and method

An apparatus and method for uniquely detecting pits on a smooth surface by irradiating an area of the surface; separately sensing radiation scattered from the surface in the near-specular region indicative of a pit and in the far-specular region indicative of a flaw and producing signals representative thereof; normalizing the near-specular signal with respect to the far-specular signal to indicate a pit; and discriminating the near-specular components of the normalized signal representative of surface pits.

Surface pit detection system and method

In the surface inspection apparatus disclosed herein, an elongate array of electro-optical shutters is interposed between a laser beam which scans across the surface to be inspected and a photodetector system which collects light scattered from the surface along the scan line. The shutters are operated in a shifting pattern in synchronism with the scanning means thereby to block unwanted regular signal components.

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Newburyport, MA, United States of America

George S Quackenbos