Swift heavy ion track formation in SiC films under high-temperature irradiation

TL;DR

This study investigates how film thickness and temperature influence swift heavy ion track formation in SiC films, revealing a transition from hillocks to craters with increasing temperature.

Contribution

It introduces a comprehensive model combining electron emission and atomic response to analyze ion track formation across various SiC film thicknesses and temperatures.

Findings

Two types of nanostructures (craters and hillocks) form after ion impacts.

Transition from hillocks to craters depends on irradiation temperature.

Transition temperature increases with film thickness, reaching about 1534 K for bulk SiC.

Abstract

It is known that swift heavy ion (SHI) irradiation at temperatures below $\sim$1000 K does not cause structural damage in the bulk SiC. However, the effect of the SiC film thickness on the formation and structure of SHI tracks over a wide range of irradiation temperatures remains unexplored. To address this gap, we used a model sensitive to irradiation temperature that describes all stages of ion track formation: from material excitation, considering the emission of excited electrons from the film surface (MC code TREKIS-3), to the reaction of the material's atomic system to the excitation (classical molecular dynamics). We observed the appearance of two different types of nanostructures on the surface of SiC films with thicknesses ranging from 10 nm to 100 nm after impacts of 710 MeV Bi ions: craters and hillocks. The transition from hillocks to craters occurs with the irradiation temperature. The transition temperature increases with the film thickness, tending to $\approx 1534 \pm 100$ K for the surface of bulk SiC.