A new alloy liquid metal ion source (LMIS) has been developed which may be used for the focused ion beam patterning of magnetic elements into GaAs wafers. The GaMn alloy source had a composition of 90% Ga and 10% Mn by atomic weight. The source displayed good operating characteristics with stable and low emission currents. Typical turn-on currents were about 10 μA at an extraction voltage of -6 kV. The maximum current attained for the Mn2+ beam was 0.8 nA (current density ∼0.1 A/cm2), which would allow the real-time patterning of approximately (100 μm)2 of Ga0.95Mn 0.05As during the wafer growth. Beam resolution was 5 μm, and with the excellent mass separation between the different ion species, and reasonably large beam currents, it demonstrates the suitability of the source for high-resolution device patterning.
- Focused ion beam
- Liquid metal ion source