Atomistic simulation of ion irradiation of semiconductor heterostructures

TY - JOUR

T1 - Atomistic simulation of ion irradiation of semiconductor heterostructures

AU - Fridlund, Christoffer

AU - Laakso, Jarno

AU - Nordlund, Kai

AU - Djurabekova, Flyura

N1 - Volume: Host publication title: Proceedings of the 20th International Conference on Ion Beam Modification of Materials (IBMM 2016) Proceeding volume: 409

PY - 2017/10/18

Y1 - 2017/10/18

N2 - Recently the possibility to use ion beam mixing combined with suitable annealing has been suggested as a possible means to synthesize individual silicon quantum dots in a silica layer, with the possibility to function as single-electron transistors. For this to work, it is necessary to have a careful control of the ion beam mixing in Si/SiO2/Si heterostructures, as well as understand the nature of not only the composition, but also the chemical modification of the SiO2 layer by the mixing with Si. We describe here a procedure to synthesize Si/SiO2/Si heterostructures in molecular dynamics, with an energy minimization scheme to create strong and stable interfaces. The created heterostructures are irradiated at energies and fluences matching corresponding experiments. The results show a considerable degree of interface mixing, as expected. They also show some densification of the silica layer due to recoil implantation, and formation of a considerable number of coordination defects. Due to the strong covalent bonding in silicon and silica, the densification is not fully elastically relaxed even in the presence of a nearby surface.

AB - Recently the possibility to use ion beam mixing combined with suitable annealing has been suggested as a possible means to synthesize individual silicon quantum dots in a silica layer, with the possibility to function as single-electron transistors. For this to work, it is necessary to have a careful control of the ion beam mixing in Si/SiO2/Si heterostructures, as well as understand the nature of not only the composition, but also the chemical modification of the SiO2 layer by the mixing with Si. We describe here a procedure to synthesize Si/SiO2/Si heterostructures in molecular dynamics, with an energy minimization scheme to create strong and stable interfaces. The created heterostructures are irradiated at energies and fluences matching corresponding experiments. The results show a considerable degree of interface mixing, as expected. They also show some densification of the silica layer due to recoil implantation, and formation of a considerable number of coordination defects. Due to the strong covalent bonding in silicon and silica, the densification is not fully elastically relaxed even in the presence of a nearby surface.

KW - 114 Physical sciences

U2 - 10.1016/j.nimb.2017.04.034

DO - 10.1016/j.nimb.2017.04.034

M3 - Conference article

VL - 409

SP - 14

EP - 18

JO - Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms

JF - Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms

SN - 0168-583X

ER -