Totowa, NJ., Oct. 17-- ECI Technology has been assigned a patent (8,008,087) developed by three co-inventors for a "Analysis of silicon concentration in phosphoric acid etchant solutions." The co-inventors are Eugene Shalit, of Washington Township, NJ, Julia Tyutina, of Bayonne, NJ, and Peter Bratin, of Flushing, NY.
The abstract of the patent published by the U.S. Patent and Trademark Office states: "Low concentrations of silicon in an etchant solution are analyzed by adding a predetermined concentration of fluoride ions to a test solution comprising a predetermined volume of the etchant solution, and measuring the concentration of fluoride ions in the test solution. Reaction with silicon ions in the test solution reduces the concentration of fluoride ions, which are present in stoichiometric excess, so that the silicon concentration of the etchant solution can be calculated from the difference between the predetermined and measured concentrations of fluoride ions in the test solution. The method is especially suited for analysis of silicon nitride etchants comprising a high concentration of phosphoric acid." The patent application was filed on March 25, 2010 (12/661,968).
The full-text of the patent can be found at http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PTXT&s1=8,008,087&OS=8,008,087&RS=8,008,087.