Patent ID: 8953030
Filing Date: 2015-02-10
Classification: G01N

Abstract:
1. A camera system for viewing, as opposed to providing a beam of electromagnetic radiation to conduct measurements on a surface of a sample, in functional combination with a reflectometer, ellipsometer, polarimeter or the like system: wherein said reflectometer, ellipsometer, polarimeter or the like system comprises: such that in use said source of a beam of electromagnetic radiation causes a beam of electromagnetic radiation to interact with a sample placed on said stage and reflect into said detector, such that sample characterizing data is produced thereby, said beam of electromagnetic radiation defining an “X”-“Z” plane in an orthogonal “X”, “Y” and “Z” axis system; and said camera system for monitoring the surface of said sample comprises: each of said camera sensor plate, focusing means and sample supporting stage each being oriented in identifiable planes, wherein: such that in use when said camera is positioned to observe a sample placed on said stage for supporting a sample along a camera viewpoint locus (VL), said camera viewpoint locus forms an angle alpha (α) with respect to the plane of said camera sensor plate, and proceeds from said camera sensor plate along a substantial perpendicular to the plane of said focusing means and along its optical axis, and such that said camera viewpoint locus further forms an oblique angle of incidence beta (β) with respect to a normal to a surface of said sample, said camera being offset in both “Y”, and “Z” directions from said “X”-“Z” plane; said camera sensor plate, focusing means and stage for supporting a sample being oriented with respect to one another such that a projected perpendicular to the plane of the camera sensor plate, a projected plane of the sample surface and a projected plane of the focusing means intersect at a common point, and such that the following condition is substantially met: where “X” is the distance from the camera sensor plate, at the point at which said beam passes therethrough, to a center of said focusing means, and “f” is the focal length of said focusing means and where alpha (α) and beta (β) were defined above; such that, in use the camera provides a focused view of the sample over the area thereof viewed, while ellipsometric or the like data is acquired at small angles-of-incidence that are unattainable when the camera is present along the “Z” axis where it interferes with the positioning of said source of a beam of electromagnetic radiation and said detector.