Atomistic Insights into Plasma–Material Interactions in Al-Doped TiO₂ via Molecular Dynamics

As semiconductor devices continue to scale down, high-k materials are required to mitigate leakage currents. Al-doped TiO₂ (ATO) has emerged as a promising candidate due to its high permittivity. To improve the electronic properties of ATO, an in-situ post-doping plasma (PDP) process was recently introduced.

In this study, Molecular Dynamics simulations were performed to investigate plasma–material interaction mechanisms during the PDP process, which are difficult to observe experimentally. By mimicking ion bombardment conditions, we quantitatively analyzed local energy transfer from incident Ar ions.

The results show that energy transfer from Ar ions facilitates the diffusion of surface Al dopants into the bulk region. Dopant depth profiles confirmed a gradual increase in penetration depth. Additionally, radial distribution function analysis revealed sharpening of peaks, indicating that energy transfer promotes surface crystallinity through atomic rearrangement.

These findings provide atomistic insight into dopant redistribution and structural reordering under plasma conditions, offering a fundamental understanding of ion-mediated energy transfer at the atomic scale. This insight is applicable to a broad range of plasma-assisted surface modification processes.