Abstract
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)
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)
| Original language | English |
|---|---|
| Publication status | Published - 23 Mar 2017 |