Dresden 2017 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 79: Poster: New Materials
HL 79.11: Poster
Thursday, March 23, 2017, 15:00–19:00, P2-OG3
A New Concept for Doping Silicon and its Nanostructures: Modulation Doping using Al-induced Acceptor States in SiO2 — •Daniel Hiller1 and Dirk König2 — 1Laboratory for Nanotechnology, IMTEK, University of Freiburg, Germany — 2University of New South Wales (UNSW), Sydney, Australia
Silicon nanostructures are omnipresent in fundamental research (quantum dots, nanowires) but are also approached in future technology nodes of the microelectronics industry. Several fundamental physical principles based on diffusion, statistics, and quantum confinement, impede efficient and reproducible impurity doping of nano-Si with e.g. P or B.
In this presentation, we highlight a novel concept: Heterostructure modulation doping of Si using an acceptor state of Al-atoms in SiO2. This state is located 0.5 eV below the Si valence band and captures electrons from the Si over a distance of several nanometers, leaving behind holes as majority carriers [1]. We demonstrate experimental evidences of this mechanism: fixed negative charges and increased tunnelling currents in SiO2:Al thin films, induced holes in modulation doped Si quantum wells, and PL quenching of modulation doped Si nanocrystals.
[1] D. König & D. Hiller et al., Sci. Rep., under review (2016)