Examining Different Regimes of Ionization‐Induced Damage in GaN Through Atomistic Simulations

Abstract

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.

Charge Collection Efficiency of Single GaN Core–Shell Wires Assessed by High-Precision Ion-Beam-Induced Charge Measurements

“…1 Moreover, owing to its very good radiation resistance, GaN is also a very interesting material for applications that involve ionizing radiation. 2 The main characteristics that provide high stability in extreme radiation environments are the high displacement energies of the atoms (45 eV for Ga atoms and 109 eV for N atoms 3 ) and the very good dynamic annealing properties, even below room temperature. 4 Additionally, its wide bandgap of 3.4 eV 5,6 allows operation in high-temperature environments and also makes the detector insensitive to visible radiation.…”

“…GaN is a wide-bandgap semiconductor with many interesting properties and a material that has revolutionized different semiconductor device markets, with special emphasis on the lighting industry . Moreover, owing to its very good radiation resistance, GaN is also a very interesting material for applications that involve ionizing radiation . The main characteristics that provide high stability in extreme radiation environments are the high displacement energies of the atoms (45 eV for Ga atoms and 109 eV for N atoms) and the very good dynamic annealing properties, even below room temperature .…”