New avenues to an old material: controlled nanoscale doping of germanium

作者：Scappucci Giordano^*; Capellini Giovanni; Klesse Wolfgang M; Simmons Michelle Y

来源：Nanoscale, 2013, 5(7): 2600-2615.

DOI：10.1039/c3nr34258a

We review our recent research into n-type doping of Ge for nanoelectronics and integrated photonics. We demonstrate a doping method in ultra-high vacuum to achieve high electron concentrations in Ge while maintaining atomic-level control of the doping process. We integrated this doping technique with ultra-high vacuum scanning tunneling microscope lithography and femtosecond laser ablation micron-scale lithography, and demonstrated basic components of donor-based nanoelectronic circuitry such as wires and tunnel gaps. By repetition of controlled doping cycles we have shown that stacking of multiple Ge: P two-dimensional electron gases results in high electron densities in Ge (%26gt;10(20) cm(-3)). Because of the strong vertical electron confinement, closely stacked 2D layers - although interacting - maintain their individuality in terms of electron transport. These results bode well towards the realization of nanoscale 3D epitaxial circuits in Ge comprising stacked 2DEGs and/or atomic-scale Ge: P devices with confinement in more dimensions.

• 出版日期2013