Ion Irradiation Simulations to Study Quantum Dot Formation in III-V Semiconductors

Toriyama, Michael; Lively, Michael; Holybee, Brandon

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https://hdl.handle.net/2142/99872 Copy

Description

Title

Ion Irradiation Simulations to Study Quantum Dot Formation in III-V Semiconductors

Author(s)

• Toriyama, Michael
• Lively, Michael
• Holybee, Brandon

Contributor(s)

Allain, Jean-Paul

Issue Date

2018-04

Keyword(s)

• Nuclear, Plasma, and Radiological Engineering
• Ion Irradiation
• Molecular Dynamics
• Gallium Antimonide
• Compositional Depth Profile
• Ion-Surface Interactions

Abstract

Quantum dot (QD) formation on III-V semiconductor surfaces using ion irradiation has attracted significant experimental and theoretical interests for industrial applications. Various models have claimed to predict QD formation on gallium antimonide (GaSb) surfaces, but a glaring knowledge gap highlighted by recent experiments suggest a preliminary morphology of the compositional depth profile leading to QD emergence. To understand how the evolving composition induces prompt effects preceding QD formation, atomistic simulations are implemented using Molecular Dynamics (MD) to simulate Kr+ ion impact simulations onto the GaSb surface. We present single ion bombardment simulations on GaSb surfaces with altered compositions, which elucidate the dependence of ion-surface interactions on surface composition. The size and shape of ion range, energy transfer, and momentum transfer distributions exhibit a strong dependence on interfacial effects produced by layers of different compositions. Specifically, we find that the distributions exhibit peaks at the interfaces, which means that incident ions are “trapped” by the presence of interfaces. Using this and the self-crystallization of Sb clusters observed in earlier simulations, we derive a hypothesis on quantum dot emergence from the subsurface based on sputtering. The results not only elucidate the dominant role of surface composition in driving compositional morphology, but also quantify fundamental ion-surface interactions attributed to the compositional depth profile.

Type of Resource

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Copyright and License Information

• Copyright 2018 Michael Toriyama
• Copyright 2018 Michael Lively
• Copyright 2018 Brandon Holybee

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