Suspended quantum dot fabrication on a heavily doped silicon nanowire by suppressing unintentional quantum dot formation

We aim at embedding a quantum dot on a suspended nanowire by solving the problem of unintentional quantum dot formation, which exacerbates in a suspended nanowire. The origin of this worsening is the higher potential barrier presumably owing to the enhancement of random-dopantinduced potential fluctuation and/or higher degree of surface roughness and surface trapped charges on suspended nanowires. The higher barrier was successfully decreased by adopting a higher doping concentration as well as wider constriction patterns. Consequently, we can control the quantum dot formation in the suspended nanowire and successfully defined a single-quantum dot by patterning the double constrictions on the heavily doped suspended nanowire.