Molecular Dynamics Study on Enhanced Cu Coverage of Trench Filling with Low-Index Ta Surfaces

作者:Hong Rong Tai*; Yang Jaw Yen
来源:Japanese Journal of Applied Physics, 2012, 51(6): 06FF14.
DOI:10.1143/JJAP.51.06FF14

摘要

The Cu coverage of trench filling enhanced by different low-index surfaces of tantalum in physical vapor deposition is studied by molecular dynamics simulation with the embedded atom method (EAM) as the interaction potential for the present alloy metal system. The deposition morphologies and bottom step coverage enhancement of trenches with three different aspect ratios are examined. It is found that the Cu adatom on Ta(110) with uniform and low surface diffusion barrier energy and that on Ta(111) with high surface energy lead to the improvement of the surface diffusion of Cu adatoms. The shadowing effect is inhibited on Ta(110) and Ta(111) such that the bottom step coverage of the trench is enhanced markedly at an early stage and the final coverage of trench filling is improved significantly. Also, the texture of deposition on the trench with Ta(110) has a uniform structure owing to the low surface energy, while that with Ta(111) has a nonuniform structure owing to the high surface energy on the sidewall.

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