A FREEMAN ION-SOURCE FOR OXYGEN IONS IN AN IMPLANTER

A Freeman ion source for the LC-2F implanter was improved. In this sou rce the filament is a 2-mm-diam tungsten wire covered with a LaB6 cyli nder. The discharge chamber is made of antioxidation and high temperat ure resistant stainless steel. The source lifetime is more than 10 h i n pure oxygen discharges, and no oxidation phenomenon occurs on the di scharge chamber during long time operation. The source discharge and e xtraction characteristics are similar to those used before for BF3 and P discharge. So the source can be used in a wide range of microelectr onics and material science.