本研究旨在探討Ni-Al金屬玻璃薄膜作為銅金屬與錫金屬之間擴散阻障層的相關機械性質與擴散行為，使用分子動力學方法搭配Finnis-Sinclair勢能函數針對Ni-Al薄膜與多晶銅金屬所構成之Cu/Ni-Al阻障層雙層結構系統在不同條件之下如Ni-Al製備冷卻速率、合金比例以及系統溫度等進行單軸拉伸、剪切試驗以及定溫擴散模擬，藉以分析其各項材料性質，亦透過共同近鄰原子分析(CNA)與鍵對分析(HA指數)等方法研究Ni-Al阻障層之結構型態。本研究之拉伸與剪切試驗模擬結果顯示隨著Ni-Al冷卻速率增加，雙層結構系統的強度會有下降的趨勢，其主要變形區域由多晶銅轉移至Ni-Al阻障層內，變形機制亦從多晶銅晶界與疊差結構之滑移轉變為Ni-Al內部平均分布之微小應變區域，且變形行為較偏向於延性。針對合金比例的部分，當Ni-Al金屬玻璃之Ni原子比例增加時強度則有所提升。藉由在不同溫度與拉伸、剪切負載速率下之模擬可發現Cu/Ni-Al雙層結構在較高溫度之下會有流動軟化的情形而導致強度下降且延性增加，在較高負載速率下強度則會提升。擴散模擬的結果顯示在相同溫度之下，大致上Ni-Al冷卻速率越高則雙層結構中銅原子的擴散係數越低，當Ni原子比例增加時銅原子擴散係數亦有下降的趨勢，Ni-Al金屬玻璃抑制銅原子擴散的能力相較於多晶態Ni-Al明顯較佳，為其內部隨冷卻速率上升而大量增加之ISRO短程有序結構所導致。上述相關研究結果可作為在電子裝置封裝中使用Ni-Al金屬玻璃薄膜作為擴散阻障層時之設計依據。

In this work, a heterogeneous bilayer model with lower polycrystalline copper layer and upper Ni-Al thin-film layer was introduced, applying to uniaxial tensile, shear and diffusion tests under various conditions to investigate the mechanical properties and diffusion behavior of Ni-Al thin-film metallic glass that used as a diffusion barrier between copper and tin. Molecular dynamics simulation with Finnis-Sinclair potential was adopted to carry out the whole work. Simulation results indicate that the strength of bilayer systems decrease with increasing Ni-Al cooling rates, main deformation region translates from polycrystalline copper to Ni-Al barrier. Moreover, deformation mechanism switches from propagation of grain boundaries and stacking faults of copper to small strain region accumulation of Ni-Al and ductile-like behavior is observed. For alloy ratio, strength of bilayers increases with higher Ni content of Ni-Al metallic glasses. Strength decreasing due to flow softening phenomenon can be seen from simulations under higher temperatures. Conversely, rising loading rates can induce higher strength. Results of diffusion tests reveal that MSD and diffusion coefficients of Cu atoms reduce with increasing cooling rates and Ni content of Ni-Al. It is evident that the performance of Cu diffusion mitigation of Ni-Al metallic glasses is better than polycrystalline Ni-Al due to high fraction of ISRO structure inside Ni-Al along with cooling rates. Results of this work can be a designing guideline for using Ni-Al thin-film metallic glass as a diffusion barrier in electronic packaging industries.

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