Nov 22, 2013
Monte Carlo simulations of ion beam-induced sputtering
The gas-filled ion source (GFIS) is widely studied because it can be employed in a number of important areas, including circuit editing, nanoscale imaging, lithography, and nanoscale synthesis. While most of the early work in this field was dedicated to the helium ion source, a stable neon GFIS has recently been demonstrated. A team at Oak Ridge National Laboratory and the University of Tennessee Knoxville, both in the US, has now developed Monte Carlo simulations for both electron and ion beams to model beam-induced deposition, etching and the physical sputtering of materials emulating nanoscale focused ion beam etching in the gas field ion microscope.
Ion beam induced deposition and etching with inert He+ and Ne+ ion beams logically follow on from the more traditional gallium ion beams since they have masses between those of electrons and gallium ions. For example, the electron has a mass of 5 x 10–4 amu, helium, 4 amu, neon, 20 amu, and gallium, 70 amu. Being able to select the mass of the ions employed is important because it allows researchers to control the electronic and nuclear energy loss components and, thereby, select specific chemical and physical etching components. In this way, the ion implant range can be varied – something that can help avoid ions that may deleteriously damage the underlying substrate.
More details about the research can be found in the journal Nanotechnology 24 495303.
About the author
The team, which has been working in this field for the last few years and which has made significant contributions to the nanotechnology community, includes scientists from Oak Ridge National Laboratory and professors, postdocs and graduate students from the University of Tennessee Knoxville. The group, supervised by Prof. Philip D Rack boasts both experimental and computer simulation facilities. This research was performed by Dr Rajendra Timilsina, a postdoc in the University of Tennessee Knoxville group. He has developed simulations for a wide range of electron and ion beam energies and for many single and compound substrates. The simulation work described in this article is unique in induced beam processing. The work was funded by the Semiconductor Research Corporation (SRC).