Modeling of long-term defect evolution in heavy-ion irradiated 3C-SiC: Mechanism for thermal annealing and influences of spatial correlation

Abstract

Based on the parameters from published ab-inito theoretical and experimental studies, and combining Molecular Dynamics (MD) and kinetic Monte Carlo (KMC) simulations, a framework of multi-scale modeling is developed to investigate the long-term evolution of displacement damage induced by heavy-ion irradiation in cubic silicon carbide. The isochronal annealing after heavy ion irradiation is simulated, and the annealing behaviors of total interstitials are found consistent with previous experiments. Two annealing stages below 600K and one stage above 900K are identified. The mechanisms for those recovery stages are interpreted by the evolution of defects. The influence of the spatial correlation in primary damage on defect recovery has been studied and found insignificant when the damage dose is high enough, which sheds light on the applicability of approaches with mean-field approximation to the long-term evolution of damage by heavy ions in SiC.

Real-Time Diagnostics of 2D Crystal Transformations by Pulsed Laser Deposition: Controlled Synthesis of Janus WSSe Monolayers and Alloys

“…The migration barrier for S vacancies in MoS 2 is 0.6 eV 52 but the migration barrier can decrease in the presence of neighboring vacancies 53,54 by as much as 80%. 55 The E a1 = 0.12 eV we measured is more consistent with energy barriers for interstitial-vacancy recombination/annihilation, 56,57 while E a2 = 0.90 eV may be related to slower processes like vacancy migration. Detailed atomistic characterization of the defect healing mechanisms, both experimental and theoretical, are planned as the subject of future investigations in order to more quantitatively assign processes to the observed rates.…”

Thermal annealing and evolution of defects in neutron-irradiated cubic SiC

“…Their first stage of annealing at 600 °C as well as considerable decrease in the intensity of the BG spectrum correlate with annealing of partly amorphized regions in the 4H-SiC sample implanted with aluminum ions [23] and theoretical calculations of defects thermal annealing mechanisms in heavy-ion irradiated 3C-SiC [24]. Further, the BG line gradually decreases its intensity.…”

Radiation-induced mobility of small defect clusters in covalent materials

“…Such high barriers explain why models of defect evolution in SiC have assumed clusters to be immobile even at elevated temperatures (e.g., Ref. [10,11]) and why the nature of such clusters, their resistance to high-temperature annealing, and their effects on opto-electronic properties have been a subject of many discussions in the semiconductor literature [12,13].…”

“…Such high barriers explain why models of defect evolution in SiC have assumed clusters to be immobile even at elevated temperatures (e.g., Ref. [10,11]) and why the nature of such clusters, their resistance to high-temperature annealing, and their effects on opto-electronic properties have been a subject of many discussions in the semiconductor literature [12,13].In this letter, we report a direct observation of interstitial clusters diffusion in bulk SiC under the influence of electron radiation at room temperature. Although it is known that in metals…”