Zeta has integrated a Spectroscopic Reflectometer that is capable of measuring multi-stack film thickness or n&K values if the thickness is known.
It uses a common light source, optics path and camera so that the film thickness measurements are in the same location as the 3D measurements. A graphic indicator on the Live Image screen clearly shows the user where the film thickness measurement is being taken.
|Typical Optical Parameters|
|Light source||White HBLED 430 nm to 750 nm|
|Spectral Resolution||1 nm|
|Range||30 to 50,000 nm|
Spectrum for a 2000Å (nominal) nitride film
2.39 nm high asperity.
MicroPit Defect on Magnetic Disk Media
23.76 nm deep micro pit.
ZFT works on some of the least reflective surfaces such as a solar cells with reflectivity of less than 0.5%.
Many film thickness tools have difficulty in obtaining any signal from these type of surfaces, since they depend on specular reflected light to calculate phase change or other such parameters. The broadband white light and the normal incidence allow the tool to be used with a variety of optically transparent films