The widespread adoption of gGaN in radiation-hard semiconductor devices relies on a comprehensive understanding of its response to strongly ionizing radiation. Despite being widely acclaimed for its high radiation resistance, the exact effects induced by ionization are still hard to predict due to the complex phase-transition diagrams and defect creation-annihilation dynamics associated with group-III nitrides. Here, the Two-Temperature Model, Molecular Dynamics simulations and Transmission Electron Microscopy, are employed to study the interaction of Swift Heavy Ions with GaN at the atomic level. The simulations reveal a high propensity of GaN to recrystallize the region melted by the impinging ion leading to high thresholds for permanent track formation. Although the effect exists in all studied electronic energy loss regimes, its efficiency is reduced with increasing electronic energy loss, in particular when there is dissociation of the material and subsequent formation of N2 bubbles. The recrystallization is also hampered near the surface where voids and pits are prominent. The exceptional agreement between the simulated and experimental results establishes the applicability of the model to examine the entire electronic energy loss spectrum. Furthermore, the model supports an empirical relation between the interaction cross sections (namely for melting and amorphization) and the electronic energy loss.
Bibliographical noteKAUST Repository Item: Exported on 2022-11-04
Acknowledgements: Financial support by FCT, Portugal and FEDER is acknowledged (PTDC/CTM-CTM/28011/2017, LISBOA-01-0145-FEDER-028011, UID/05367/2020). M.S. thanks FCT Portugal for his PhD grant (SFRH/BD/111733/2015) and the EU H2020 Project No. 824096 “RADIATE.”. The authors acknowledge the GANIL for SHI beamtime available under the project CIMAP/IPAC2016/LB/P1110-M-S. The authors thank I. S. Roqan (KAUST) for the GaN samples.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
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