System and Method for Performing Ellipsometric Measurements on an Arbitrarily Large or Continuously Moving Sample

A computer readable medium for storing instructions, which when executed by a computer, causes the computer to calibrate an apparatus for ellipsometric measurements performed on an arbitrarily large sample, using a visible sample reference frame, said instructions for:

• projecting a first laser beam spot, from an incident laser source onto a sample, said first laser beam spot location being within the sample reference frame;
• analyzing the position of said first laser beam spot relative to the center of the sample reference frame;
• and
• adjusting an initial physical location using at least one of a plurality of physical elements comprising the apparatus for ellipsometric measurements to achieve a first beam spot location being located about the center of the sample reference frame.

An apparatus for performing ellipsometric measurements on an arbitrarily large sample, using a visible sample reference frame, the apparatus comprising:

• a semi-circular track;
• a first laser source pivotally mounted to a first stage, said first stage mechanically coupled to said semi-circular track, wherein said first laser source projects a laser beam within the sample reference frame;
• a second laser source wherein said second laser source projects a laser beam within the sample reference frame;
• and
• a detector, pivotally mounted to a second stage, said second stage mechanically coupled to said semi-circular track, wherein said detector is movable to receive laser light reflected off the sample;
• wherein the first stage and the second stage move in tandem such that a radial movement of the first stage through an arc along the semi-circular track is equal and opposite to a radial movement of the second stage through an arc along the semi-circular track.