The n&k Premise
A Recipe for Successful Scatterometry and Thin Film Measurements:
Start with excellent raw data with optimized signal-to-noise ratio
over the widest possible wavelength range,COMBINE WITHPhysically valid models for analysis of the raw data.
Accurate and precise measurements of the most challenging OCD
and thin film structures that cover current and future applications.
The n&k premise provides the foundation for all n&k Scatterometers and Thin Film Metrology tools
- Measurements are taken over the widest possible wavelength range either from
190nm –1,000nm or 190nm – 15,000nm
- Optical design involves n&k’s patented reflective optics for which most of the photons (signal) are able to reach the detector, thus optimizing the signal-to-noise of the measured raw data
- The physically valid Forouhi-Bloomer (F-B) Dispersion Equations for n and k as functions of
wavelength, are utilized for thin film analysis. The F-B equations are combined with the
physically valid Rigorous Coupled Wave Analysis (RCWA) for analysis of OCD structures
(2D trenches and 3D holes)
Basically, inadequate results for OCD and thin film measurements may occur when a
scatterometer or thin film metrology tool does NOT satisfy the n&k premise.