Effects of collision cascade density on radiation defect dynamics in 3C-SiC

L B Bayu Aji,J B Wallace,S O Kucheyev

doi:10.1038/srep44703

L B Bayu Aji, J B Wallace + Show 1 more

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https://doi.org/10.1038/srep44703

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Abstract

Effects of the collision cascade density on radiation damage in SiC remain poorly understood. Here, we study damage buildup and defect interaction dynamics in 3C-SiC bombarded at 100 °C with either continuous or pulsed beams of 500 keV Ne, Ar, Kr, or Xe ions. We find that bombardment with heavier ions, which create denser collision cascades, results in a decrease in the dynamic annealing efficiency and an increase in both the amorphization cross-section constant and the time constant of dynamic annealing. The cascade density behavior of these parameters is non-linear and appears to be uncorrelated. These results demonstrate clearly (and quantitatively) an important role of the collision cascade density in dynamic radiation defect processes in 3C-SiC.

Highlights

The understanding of radiation damage phenomena in SiC is desirable for the development of radiation tolerant SiC-based nuclear ceramics and for the control of lattice disorder associated with ion-beam processing of electronic devices[1,2]
We focus on the Rgen effects on damage buildup and dynamic annealing (DA) in 3C-SiC, which is the cubic polymorph of SiC
Damage buildup studies are traditionally performed by bombardment with continuous ion beams[3]

Summary

OPEN Effects of collision cascade density on radiation defect dynamics in

3C-SiC received: 20 September 2016 accepted: 13 February 2017 Published: 17 March 2017. Our understanding of radiation damage processes in SiC remains limited, in regimes with pronounced dynamic annealing (DA) Such DA refers to the migration and interaction of point defects (during irradiation) after the thermalization of ballistically generated collision cascades for time scales ≳1 ps. For relatively low E ions used in the present work (with an electronic energy loss ≲1 keV nm−1), electronic excitation effects ( poorly understood and requiring further studies) are typically negligible for metals and predominantly covalent ceramics such as SiC3,4 In this case, the m effect is related to the difference in the density of collision (sub)cascades (ρcascade) generated by different ion species. Damage buildup studies are traditionally performed by bombardment with continuous (rather than pulsed) ion beams[3] Such experiments provide limited insight into the dynamics of point defect interaction during irradiation.

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