Ellipsometry

Ellipsometry determines film thickness and optical material properties by measuring how the polarization state of light changes upon reflecting off a sample.

What's measured

When polarized light hits a sample, the amplitude and phase of the reflected wave change in a characteristic way. This change is typically described by two quantities known as Psi and Delta.

From measurement to result

Using physical models, Psi and Delta can be converted into film thickness, refractive index, and absorption properties of a sample — often with sub-nanometer accuracy.

Applications

• Monitoring thin films in semiconductor manufacturing.
• Characterizing coatings in materials science.
• Studying biological and chemical interfaces.
• Determining surface roughness.

The big advantage: ellipsometry is non-destructive, highly precise, and delivers results within seconds.