Patent ID: 8274645
Filing Date: 2012-09-25
Classification: G01B,G03F

Abstract:
1. A vacuum processing apparatus for obtaining in-situ scatterometry data comprising: a process chamber configured to perform a plasma process on a workpiece disposed at an arbitrary fixed orientation; an optics assembly to focus an optical spot having an area smaller than the workpiece onto a periodic array disposed on the workpiece while the workpiece is disposed in the process chamber; a linear polarizer in an optical path of the optics assembly and to rotate a polarization axis through a plurality of angular positions relative to the fixed workpiece orientation; a flash lamp coupled to the optical path to periodically illuminate the periodic array within the optical spot; a trigger line to trigger the flash lamp when the polarizer is rotated to a predetermined angular position relative to the fixed workpiece orientation; and a spectrometer to output reflectance spectra collected from the periodic array when periodically illuminated by the flash lamp.