A transparent or partially absorbing film on Si wafer

Contents

1 General Oscillator Model Fitting

1.1 Procedure for UV Absorbing Films

2 Examples of the operating procedure

2.1 A transparent film

2.2 A partially absorbing film

1. General Oscillator Model Fitting

• General Oscillator Model functions describe the real (ɛ1) and imaginary (ɛ2) parts of the dielectric functions (see Kramers-Kronig Relation), which absorption regions in the spectrum must account for.
  • If you handle the transparent region, then set ɛ2 = 0.
  • If you handle the absorbing region, then add ɛ2 to ɛ1.
• General Oscillator Model functions are constrained by Kramers-Kronig consistency, but Cauchy model function (see Cauchy Layer) is not.
• The General Oscillator Layer window is shown below.
• Warning: Do not touch n and k in the "Opt Const Fit" boxes.

1.1 Procedure for UV Absorbing Films

1. Cauchy Fit: transparent region only
2. Pt-by-Pt Fit: all wavelengths,
   1. fix thickness, then perform pt-by-pt fit
   2. Build Genosc from tabulated ‘cauchy’
3. Match n,k using Genosc: fit reference – first e2, then e1
4. Fit Ψ & Δ data using new Genosc model

2. Examples of the operating procedure

2.1 A transparent film

2.2 A partially absorbing film