PERFORMANCE OF THE ADVANCED MEVVA IV 80-10 METAL-ION IMPLANTATION SYSTEM

An advanced version of the MEVVA IV (metal vapor vacuum arc) metal ion source has been incorporated into a complete metal ion implantation system. Equipped with a remotely controlled rotating cathode holder, allowing up to eight different ion species to be extracted without breaking vacuum, this advanced version of the MEVVA ion source operates without a plasma-guiding magnet, and has better vacuum outgassing, leading to enhanced operation. Performance tests have been run with a large variety of materials, including carbon, silicon, titanium, chromium, iron, cobalt, nickel, copper, yttrium, zirconium, molybdenum, ruthenium, silver, tungsten, rhenium, and platinum. Extended full power tests with titanium at 80 kV extraction voltage indicate beam currents at the 10 mA power supply limit can be sustained for hours with voltage maintaining stability. The average extracted current exceeded the design current of 5 mA for all species tested. Even for a heavy ion, molybdenum, an average current of 9.5 mA at 80 kV was sustained. X-ray fluorescence was used to measure the beam profile. The beam is nearly gaussian, with a half width at half maximum in excess of 7.5 cm at a distance of 90 cm from the source. The ion source is mounted vertically without a mass analyzer. Components to be implanted are mounted on a 50 cm diameter rotating table approximately 90 cm from the ion source. Other system features include an IR temperature monitor, insertable beam stop, full computer controls with automatic venting and pump down, and closed loop cooling system.