The TMS Scatterometer (left) is a table top instrument used to scan silicon wafers, and other smooth reflectors. Results are given as TIS (total integrated scatter) and or FS (fractional scatter) according SEMI Standard. When appropriate the TIS can be converted to the surface rms roughness and a sample roughness map presented. For rougher samples, or samples scattering from other sources (such as surface films) the FS (integrated scatter normalized by the specular reflection) can be mapped. The FS is a useful parameter for monitoring production line surfaces. The sample areas to be scanned are programmable. The TMS can soon be ordered with automated wafer handling robots.
The 5 scatterometers side-by-side comparison chart