Fusion Systems Corp, Rockville, Maryland maker of semiconductor capital equipment and ultra-violet curing systems, has filed with the Securities & Exchange Commission to go public with an initial offer of 5.25m shares, just 750,000 new, at a target price of $18 to $20 a time and will use net proceeds for working capital. Lehman Brothers, Robertson, Stephens & Co LP and Salomon Brothers Inc will manage the issue in the US, Lehman elsewhere.