Ellipsometry is an optical technique used to characterize the properties of thin films and surfaces. It is based on the measurement of changes in the polarization state of light reflected or transmitted from a sample.
In ellipsometry, polarized light is typically directed at an angle onto the surface of the sample. As the light interacts with the sample's surface and any thin films present, its polarization state changes. By precisely measuring these changes in polarization, ellipsometry can provide valuable information about various properties of the sample, such as its thickness, refractive index, and optical constants.
Ellipsometry finds applications in fields such as semiconductor manufacturing, thin-film deposition, surface chemistry, and materials science. It is particularly useful for characterizing thin films with nanometer-scale thicknesses and determining the optical properties of materials. Ellipsometry is a non-destructive and highly sensitive technique, making it a valuable tool for research, development, and quality control in various industries.