Angle of incidence accuracy in ultrathin dielectric layer ellipsometry measurement

摘要

Improvements in accuracy and sensitivity in mechanical-optical metrology apparatus are achieved through the use of a value for angle of incidence that is an average of positive and negative values for different arrangements of the metrology apparatus. In the ellipsometry type of metrology the average value for angle of incidence is established by using one of a reversal of light beam direction, the providing of a separate light beam mounting arm and the mechanical rotation of the sample.