Abstract: A device is disclosed for supporting semiconductor wafers or other polished, opaque plates for processing or metrology in a vertical orientation, where the wafer loading and unloading occurs in a horizontal orientation. The device consists of a pallet designed with an opening such that both sides of the wafer are exposed. The wafer is loaded into the pallet to rest on three fixed rest members extending a short distance into the opening. Moving clamp members on the frame are located for movement toward or away from the corresponding rest members. Two cylindrical rest pins are located on axes parallel to the central axis of the opening to permit the wafer to rest under the force of gravity on the rest pins when the frame is rotated to its vertical position. Special provisions are made to minimize the effects of mechanical vibration of the wafer while insuring a robust physical restraint of the wafer within the apparatus without inducing mechanical stresses which could influence the shape of the wafer.

Abstract: A system and method are provided for obtaining mapping profiles of transparent objects having a plurality of reflective surfaces. The object, the surfaces of which are to be mapped, is placed in an unequal path interferometer including a reference surface located a predetermined distance from the object. Coherent light is supplied in the interferometer from a tunable source; and multiple optical interferograms for each of the plurality of reflective surfaces are simultaneously recorded. These interferograms are simultaneously extracted through the use of a dynamically generated weighted least-square fitting technique, which separates interferograms from a set of superimposed interferograms to obtain a given interferogram for any one of the surfaces, free from errors resulting from the existence of the other interferograms.

Abstract: A low coherent noise interferometer system incorporates an improved low spatial coherence source obtained from a laser light source which supplies a beam of light through a beam-shaping lens to the first one of a set of two cascaded diffusers. One of the diffusers is dynamically changing, provided by a rotating ground glass disk. The diffusers then supply light to an interferometer of a two-beam interferometer configuration, such as Fizeau, Twyman-Green or Mach-Zehnder. In one embodiment, the first diffuser is the rotating ground glass diffuser and the second diffuser is a multi-mode optical fiber. The exit face of the fiber represents the spatially incoherent extended light source for the interferometer. The laser, the motor for driving the first diffuser and the diffusers themselves all are mounted on a separate base from the base on which the interferometer is mounted.