Estimation of an uncertainty budget and performance measurement for a dual-wavelength Twyman-Green interferometer.

In this paper, the uncertainty budget from 10 sources we claim they have direct impact on measurement is estimated. The measurement has been applied to nominal step heights of 1.34 and 1.50 μm using a dual-wavelength Twyman-Green interferometer. Experimental results show that the measured step heights match with their nominal values with expanded uncertainty in the range of 5% from the object being measured. The performance of the measurement process over time has been estimated at different confidence levels and the obtained results show that the process is maintained in a state of statistical control. To the best of our knowledge, this is the first report for estimation of uncertainty budget from a synthetic wavelength.