Advancement targets FEOL 65nm and 45nm production
FSI International has announced that the U.S. Patent and TrademarkOffice has awarded the company a patent for a method which produces ultra-uniform etch results in combination with a rinse/dry step in a single immersion tank for front-end-of-line (FEOL) critical cleans.
This advancement is part of FSI's SymFlow technology and is integrated with FSI's surface tension gradient (STG rinse/dry process for use in the MAGELLAN Immersion Cleaning System. As devices shrink and IC manufacturers' requirements become more stringent, this method of etching and rinsing in a single immersion tank increases yield and lowers costs by eliminating wafer defects generated by air exposure between traditional etch and rinse tanks. This new technology allows customers to achieve oxide etch uniformity in solutions such as dilute hydrofluoric (HF) acid and is currently being used in 65nm production and 45nm development.
"For years the IC industry has used different variations to merge thin etches with rinse steps into a single tank, but have had to sacrifice etch uniformity. FSI's technology is a novel way to combine etch and rinse and still achieve excellent uniformity in a single immersion tank," said Jeffery W. Butterbaugh, FSI's chief technologist."
The full name of FSI's latest U.S. patent No. 7,156,927 is "Transition Flow Treatment Process and Apparatus." FSI currently has more than 90 active U.S. patents in place with over 25 U.S. patents pending.
