May 17, 2007 – Targeting FEOL 65nm/45nm cleans, FSI International Inc. says it has received a US patent for a method that combines a rinse/dry step in a single immersion tank. The technology is part of FSI’s “SymFlow” technology, integrated into the company’s surface tension gradient rinse/dry process for its Magellan immersion cleaning system.

FSI says the new method of etching and rinsing in a single immersion tank eliminates wafer defects caused by wafer exposure between traditional etch and rinse tanks, helping to increase yields. It applies to oxide etch uniformity in solutions including dilute hydrofluoric (HF) acid, and is currently being used in 65nm production and 45nm development, the company claims.

“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,” said Jeff Butterbaugh, FSI’s chief technologist, in a statement. “Development of the innovative SymFlow process highlights our commitment to ensuring that our customers have access to the most advanced cleaning and etching methods available today.”