COMPARING PRISM COUPLER AND ELLIPSOMETER
VS
PRISM COUPLER
ELLIPSOME
COMPARISON OF PRINCIPLES
OPTICAL WAVEGUIDE TECHNOLOGY
Measure the modes at different angles and obtain the refractive index and thickness.
principle
POLARIZATION STATE CHANGE
Receive the intensity and polarization state of monochromatic light reflected by the sample.
YES
Obtain four parameters (refractive indices and thicknesses of both layers).
Bilayer Film
NO
Only single-layer films.
NO EFFECT
Optical Absorption
AFFECT
Highly sensitive
COMPARATIVE MEASUREMENT OF FILM THICKNESS
0.4 μm - 150 μm
Measurement Range
0.1 nm - 50 μm
YES
Direct acquisition of film thickness and refractive index.
Measurement of Film Thickness
YES
For films >50μm , initial value determination via secondary instrument is required, with compromised accuracy.
YES
Films on Transparent Substrates
NO
COMPARATIVE MEASUREMENT OF REFRACTIVE INDEX
HIGH ACCURACY
Accuracy: ±0.0005
Refractive Index Accuracy
LOW ACCURACY
Accuracy degrades by 1-2 orders of magnitude, depend on light source and detector performance.
HIGH ACCURACY
Resolution: ±0.0003
Refractive Index Resolution
LOW ACCURACY
Resolution decreases by 1-2 orders of magnitude, depend on light source and detector performance.
YES
Measures only the real component of the refractive index in bulk materials.
Measurement Of Bulk Materials
YES
Capable of measuring both real and imaginary components in bulk materials, with reduced accuracy.
YES
Enables refractive index and birefringence measurements in x, y, z directions for both thin films and bulk materials.
Anisotropy Measurement
NO
NO EFFECT
Sensitivity To Substrate Materials
AFFECT
Prior knowledge of both real and imaginary components of the substrate refractive index is mandatory.