Specific Process Knowledge/Characterization/Measurement of film thickness and optical constants
Thickness measurement of thin films can be done by optical measurement methods. At DANCHIP we have three techniques for this: Ellipsometry (ellipsometer), Reflectivity measurement (FilmTek) and prism coupling (Prism Coupler). If the thin film is not transparent for light the you must find another way to measure the thickness. You can ex. etch a pattern down to the next layer or substrate and the measure the etch step by profilometry.
Optical measurement methods:
| FilmTek 4000 | Ellipsometer | Prism couple | |
|---|---|---|---|
| Methode | Reflection | Ellipsometry | Prism Coupling |
| What is it good for: | Thick thin films up to 250 µm, wafer mapping | Very thin films down to a few Å | Refractive index measurements of silicon oxides |
| Film thickness range | <250 µm (for silicon oxides > ~75nm) | few Å to ~2µm (silicon oxide) | >? |
| Wavelength range | |||
| Thin films where we have receipes |
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