Study of atomic sputtering and transport dynamics by Monte Carlo simulation

Magnetron sputtering vacuum coating technology is widely used in Accident Tolerant Fuel (ATF) cladding materials. The growth of thin films is a crucial step in the magnetron sputtering process, closely linked to the energy and angular distribution of atoms sputtered from the target to the substrate. However, experimental investigations of atomic sputtering are challenging due to the difficulty of accurately detecting electron distributions, incident ion distributions, and quantities, especially collisions between sputtered and vacuum chamber gas atoms. In this study, the SRIM/SIMTRA programs based on the Monte Carlo method have been carried out to predict the energy and angular distributions of sputtered atoms from the target surface and to calculate the energy, angle, and number distributions of supering atoms arriving on the substrate after traversing the vacuum chamber. The results of SRIM indicate the sputtered atom distribution in the low-energy region, with the scattering angles exhibiting a ‘heart-shaped’ profile. Additionally, SIMTRA simulation results show that increasing the target-substrate distance (TSD) and vacuum chamber gas pressure leads to significant attenuation of the energy of atoms arriving on the substrate and a tendency for larger incidence angles. These simulation outcomes provide crucial theoretical guidance for optimizing magnetron sputtering coating performance for ATF cladding.