A dual source low-energy ion implantation system for use in silicon molecular beam epitaxy

Abstract Recently an ion implanter for low-energy ion doping during molecular beam epitaxy has been developed. The unit consists of a dual source injection system operating at 30 kV extraction, a beam transport system and a deceleration stage, located in an ultrahigh-vacuum MBE chamber. Tests have shown that in the energy range of 150–2000 eV target currents of up to 100 μ A can be reached with controllable beam focusing. For uniform wafer implantation the decelerated beam can be electrostatically scanned with a lateral displacement from + 70 to −70 mm at target position. To obtain sharp doping transitions, the system is designed to switch: within 1 s between the two independent microwave sources.