ABSTRACT
The unoplasmatron ion source was developed by v. Ardenne to improve the plasma density and the ion current of an electron bombardment ion source. The duoplasmatron ion source was developed by v. Ardenne as a powerful source for gas ions. It consists of two plasma regions: the lower-density cathode plasma between the cathode and the intermediate electrode (IE) and the high-density plasma between the IE and the anode. The duopigatron is a modification of the duoplasmatron with an additional reflector electrode following the anode. A duopigatron as a metal ion source for ion implantation was developed by Winter and Wolf. In the case of the high-current duopigatron ion source, the cathode-IE part acts like a plasma cathode for the multipole source between anode and reflector. Because the reflector electrode is on cathode potential, intensive sputtering occurs in the case of reflector holes of diameters smaller than the main discharge plasma.
