Patent ID: 6947850

Claim:
An apparatus for analyzing the characteristics of a geometric feature formed on a sample comprising: a spectroscopic ellipsometer system including a broad band probe beam directed to reflect off the geometric feature and a spectrometer for measuring the reflected probe beam and generating output signals, said ellipsometer including at least one of a polarizer, analyzer, and compensator n order to determine a change in phase of the probe beam as a function of wavelength; and a processor system including a master processor and a plurality of individual slave processors arranged to process data in parallel, said processor system using the output signals generated by the spectrometer to characterize the geometric feature on a real time basis, said processor system using an algorithm which includes a model of the geometric feature and which calculates a set of theoretical data at each of a plurality of wavelengths based on an initial assumption of the characteristics of the geometric feature and compares the theoretical data to normalized data derived from the output signals and thereafter modifies the initial assumption of the characteristics of the sample based on the results of the comparison and recalculates a new set of theoretical data, with the comparison and recalculation steps being repeated until the differences between the calculated theoretical data and the normalized data are minimized and wherein the calculation of theoretical data is distributed by the master processor to the slave processors and wherein each slave processor performs calculations at selected wavelengths in parallel so that the time needed to reach the desired result is minimized.