University of New South Wales:
Dr Warrick Clarke
Dr Xiaojing Zhou
Dr Andreas Fuhrer
Prof Alex
Hamilton
Dr Adam Micolich
University of Sydney:
Prof David McKenzie
Dr Nigel Marks
Dr Oliver Warschkow
University of
Newcastle: Prof Philip Smith
Dr Marian Radny
Dr Steven Schofield
Los Alamos National Laboratory, USA:
Dr Marilyn Hawley
Dr Geoff Brown
Dr Holger Grube
Program Description: Within the Atomic Fabrication and Crystal Growth Program we have
developed a unique nano to atomic-scale device fabrication strategy
in silicon to manipulate and incorporate dopants at the atomic level
using a combination of scanning probe microscopy and molecular beam
epitaxy. By adapting scanning probe systems and combining them with
crystal growth systems we have moved the STM away from just an
imaging tool, to a device patterning and fabrication tool.
Significantly we have developed a method to reliably make four
terminal electrical contact to devices patterned using the atomic
precision of the STM once they are removed from the ultra-high
vacuum microscope environment. In addition we can image each stage
of the fabrication process. In this way we are able to measure the
electrical characteristics of STM-patterned devices at cryogenic
temperatures and in high magnetic fields, allowing us to correlate
electronic device characteristics directly with dopant placement and
number.
We use this technology to develop device architectures down to the
atomic-level with the long term goal of realising atomically
precise, scalable qubits in silicon. Central to this goal is the
need to understand how to identify single dopants in silicon, how to
determine their location during each stage of the fabrication
process, how to characterise the electrical environment of the
dopants and then how to control charge and spin transfer between
dopants. Each of these fields represents a formidable challenge.
Identification and Manipulation of Single Dopants in Silicon We have an extensive program investigating the surface
chemistry and incorporation of P as the dopant using phosphine
gas as the dopant source. Using STM-based hydrogen resist
lithography we pattern P dopants in silicon with atomic
precision.
Atomic-Scale Device Fabrication Strategy We have developed a unique strategy to pattern planar dopants
in silicon with the atomic-precision of the STM. We are now
enhancing this technology to incorporate low temperature
silicon dioxide growth so that we may align surface gates to
buried STM-patterned dopants.