Damage buildup in Ar-ion-irradiated 3C-SiC at elevated temperatures
Academic Article
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
abstract
Above room temperature, the accumulation of radiation damage in 3C-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 3C-SiC irradiated with 500keV Ar ions in the temperature range of 25250C. Results reveal sigmoidal damage buildup for all the temperatures studied. For 150C and below, the damage level monotonically increases with ion dose up to amorphization. Starting at 200C, the shape of damagedepth 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 250C 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, 3C-SiC can be amorphized by bombardment with 500keV Ar ions even at 250C with a relatively large dose rate of 21013 cm2 s1, revealing a dominant role of defect interaction dynamics at elevated temperatures.
