Phosphine molecules pack on the germanium surface

ROM 2012-12
Author: G. Scappucci (1), O. Warschkow (2), G. Capellini (3), W. M. Klesse (1), D. R. McKenzie (2) and M.Y. Simmons (1)
Institute: (1)School of Physics and Centre of Excellence for Quantum Computer Technology,University of New South Wales, Sydney, NSW 2052, Australia (2)School of Physics and Centre of Excellence for Quantum Computer Technology, University of Sydney, Sydney, NSW 2006, Australia (3)Dipartimento di Fisica ‘‘E. Amaldi,’’ Universita` di Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy
Publication: Phys. Rev. Lett. 109, 076101 (2012) /
Instrument: VT SPM

Doping, the process of adding impurity atoms to semiconductors to provide free carriers for conduction, has been pivotal to microelectronics since its early stages. In particular doping germanium at high concentrations to make it highly conductive is the subject of intense research, because it lies at the heart of novel developments in integrated silicon-compatible lasers and quantum information processing devices.

Writing in Physical Review Letters, G. Scappucci and co-workers from “The University of New South Wales”, “The University of Sydney”, and “Universita’ di Roma Tre”, have demonstrated a method to densely pack dopant molecules on the Ge surface, which then self-organise to form molecular patterns with one phosphorus dopant atom every two germanium atoms. This densely packed layer is confirmed by theoretical calculations of the reaction pathway energetics which describe the initial stages of how the individual dopant atoms incorporate into the germanium surface. Such atomic scale insights provide crucial information for the future development of efficient doping processes in germanium based electronics.

Name and Email of corresponding author:
G. Scappucci (1),