In situ Si Doping in GaAs using Low-energy Focused Si Ion Beam/Molecular Beam Epitaxy Combined System

摘要

Using 200 eV focused Si ion beam (Si FIB) combined with molecular beam epitaxy (MBE) system, high-dose Si implantation in GaAs at laterally selected area was performed masklessly and the doped layer was buried by successive overlayer regrowth. From a depth profile of carriers using a capacitance-voltage (C-V) measurement of this layer, it was found that although the doping efficiency was low, carriers were still observed at the implanted region at a dose as large as 3.5xl0~(14) cm~(-2) without post-annealing. The doping efficiency was improved when the temperature of the sample during the FIB implantation was high as 150°C. The present results indicate the advantage of using low-energy ion implantation for nano-scale doping in semiconductors.