Fraunhofer Institute for Electronic Nano Systems
Spectroscopic ellipsometry with variable angle (VASE) is indispensable in the fields of research and development. As an essential characterization technique, it is an important and powerful measurement method for the investigation of new materials and processes, as well as for process control of thin and ultra-thin metallic and non-metallic layers and thin film systems.
The method measures the elliptic polarization of light being caused by linearly polarized light striking a sample and triggering interactions between the light and the material. Since ellipsometry measures the ratio of two values, it is extremely accurate and reproducible with no reference material being required. The use of spectroscopic ellipsometry (SE) leads to increased sensitivity to multiple film parameters and also eliminates the period problem associated with interference fringes in thick films. Adding multiple angles to the spectroscopic capability (VASE) provides new information due to the different optical path lengths traveled and optimizes sensitivity to unknown parameters.
