J.A. Woollam Co. - alpha-SE Ellipsometer Applications

alpha-SE^® Applications

Dielectric Films

With fast measurement speed and push-button operation, the alpha-SE® is ideal for qualifying thin films. Single-layer dielectrics on silicon or glass substrates can be measured in seconds. Log results for easy-to-use comparisons in both graphical and tabular formats.

A quick comparison of nitride thin films shows variation in the thickness and refractive index
with process condition.

alpha-SE Ellipsometer Applications - Dielectric Films comparison

Self-Assembled Monolayers

Phase information of a spectroscopic ellipsometry measurement is highly sensitive to very
thin films (<10nm). Self-assembled monolayers can be assessed and quickly compared using the alpha-SE.

alpha-SE Ellipsometer Applications - Self-Assembled Monolayers graph

For organic layers on golf, the phase parameter (Delta) shifts downward with increasing thickness.

Absorbing Films

Advanced models provide quick and efficient fits for a wide variety of materials you may encounter.

Materials

• a-Si
• poly-Si
• Diamond-like carbon
• Organic materials
• Organic LED films
• SiC

Models

• Lorentz
• Gaussian
• Harmonic
• Tauc-Lorentz
• Cody-Lorentz

alpha-SE Ellipsometer Applications - Absorbing Films graph

Coating on Glass

Patented technology allows accurate measurements on any substrate: metal, semiconductor, or glass. On transparent substrates, the alpha-SE® measures depolarization to correct for light returning from the backside of the substrate. This unwanted light can confuse other ellipsometers, but the alpha-SE® ensures accurate optical constants.

alpha-SE Ellipsometer Applications - Coatings on Glass table

The high sensitivity of alpha-SE technology provides microstructural details that you can not get from Reflectance measurements. Here a thin film of Titanium Dioxide is measured with the alpha-SE and its index is found to vary between the substrate and surface. A graded model best describes this sample.