US Patent 7652264 Filament member, ion source, and ion implantation apparatus

A filament member configured to discharge thermions may be employed in an ion source of an ion implantation apparatus. A filament member may include an anode disposed around a central portion of the filament member, a cathode disposed around a periphery of the filament and/or enclosing the anode, and at least one conductive path disposed between the anode and the cathode to discharge the thermions.