ZIC and ZSI for Shearing Interferometry
These modes use a Nomarski interferometer to quickly provide phase contrast imaging that is compatible with all objectives. These modes are not sensitive to vibrations.
ZIC is a differential interference contrast mode used to measure surface roughness on the nanometer scale. This technique is useful for detecting monolayer levels of material on a substrate. The ZIC option makes it easy to visualize and quantify monolayer contaminants on substrates like wafers and disk media.
Example of ZIC image with Zeta 3D optical profiler, showing monolayer sensitivity
ZSI is an enhanced version of ZIC. ZSI combines a proprietary phase adjustment mechanism with advanced data processing software for precision measurements. Step heights can be measured on the Angstrom level with ZSI mode. Defects, such as the 2.39 nm thermal asperity shown here on magnetic disk media, can be imaged and measured.
Thermal asperity defect on magnetic disk media, imaged using ZSI mode on the Zeta 3D optical profiler