A study of the reformulated Opticlean strip coating, distributed by Dantronix Research and Technologies of Platteville, Wis., suggests that the product removes fresh surface contaminants from silicon wafers without leaving a residue. Researchers from Acreo AB, formerly the Institute of Optical Research, in Kista, Sweden, published their results in the June 1 issue of Applied Optics.

The team monitored particulate contamination and surface residue on the 76-mm wafers with total integrated scattering, which measured the scattering of a chopped 2-mW HeNe laser beam with a 1-mm spot size. The setup was sensitive to a surface roughness of <1 Å rms.