Reconfigurable germanium transistors with low source-drain leakage for secure and energy-efficient doping-free complementary circuits

Germanium is a promising material for future VLSI devices, due to its high hole mobility. However, due to the low bandgap of 0.66 eV Ge based devices typically suffer from high reverse junction leakage und therefore high static power dissipation. In this paper, we apply a nanowire structure with multiple independent gates to suppress the leakage in off-direction to achieve off-current levels below 10-9 A/mm. In addition, the polarity of the same doping-free device can be dynamically switched between unipolar p- and n-type function, without the use of any dopants. This feature offers a variety of disrupting circuit design possibilities not accessible with CMOS, for example in the area of hardware security.