Publication Date:
2015-09-15
Description:
Above room temperature, the accumulation of radiation damage in 3 C -SiC is strongly influenced by dynamic defect interaction processes and remains poorly understood. Here, we use a combination of ion channeling and transmission electron microscopy to study lattice disorder in 3 C -SiC irradiated with 500 keV Ar ions in the temperature range of 25–250 °C. Results reveal sigmoidal damage buildup for all the temperatures studied. For 150 °C and below, the damage level monotonically increases with ion dose up to amorphization. Starting at 200 °C, the shape of damage–depth profiles becomes anomalous, with the damage peak narrowing and moving to larger depths and an additional shoulder forming close to the ion end of range. As a result, damage buildup curves for 200 and 250 °C exhibit an anomalous two-step shape, with a damage saturation stage followed by rapid amorphization above a critical ion dose, suggesting a nucleation-limited amorphization behavior. Despite their complexity, all damage buildup curves are well described by a phenomenological model based on an assumption of a linear dependence of the effective amorphization cross section on ion dose. In contrast to the results of previous studies, 3 C -SiC can be amorphized by bombardment with 500 keV Ar ions even at 250 °C with a relatively large dose rate of ∼ 2 × 10 13 cm −2 s −1 , revealing a dominant role of defect interaction dynamics at elevated temperatures.
Print ISSN:
0021-8979
Electronic ISSN:
1089-7550
Topics:
Physics
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