Negative ions for heavy ion fusion and semiconductor manufacturing applications

Abstract

Radio frequency driven multicusp source was set up to run chlorine plasma and the source performance was compared between positive and negative chlorine ion production. A maximum Cl− current density of 45 mA/cm2 was achieved at 2.2 kW of rf power with electron to negative ion ratio of 7 and positive to negative ion ratio of 1.3. 99.8% of the total negative chlorine beam was atomic Cl−. To produce negative boron ions for semiconductor manufacturing applications, a noncesiated, sputtering-type surface production ion source was constructed. An external rf antenna geometry and large LaB6 converter were implemented in the source design. Maximum B2− ion current density of 1 mA/cm2 was achieved at 800 W of rf power and −600 V converter voltage. Total B2− ion current was 1.8 mA.