| 摘要: | 目前積體電路的主流技術是銅 (Cu) 金屬製程，使用銅當作導線，以減少傳輸延遲和功耗。然而，由於銅的高擴散係數，銅線在矽基板中容易形成深能階，導致裝置性能退化。此外，銅與介電層之間的附著力較差，嚴重影響裝置效率。因此，需要研究金屬化擴散阻障層來克服銅線的固有缺點。在半導體銅製程中，鉭/氮化鉭 (Ta/TaN) 多層膜的物理氣相沉積 (PVD) 極為重要，作為PVD中的襯裡/阻障層，以防止銅與矽 (Si) 基板之間的擴散。本研究旨在增加PVD腔體套件的壽命，減少顆粒脫落並改善製程品質，對半導體行業具有實際意義。
在實際中，電弧噴塗積層製造 (ASAM) 層在腔體內部會形成一定的表面粗糙度，增強Ta/TaN薄膜的附著力。然而，當PVD薄膜達到特定厚度時會發生剝落，產生顆粒。因此，本研究利用有限元分析 (FEA) 來檢查Ta/TaN多層膜的應力分佈。模擬結果表明，薄膜剝落的主要原因是塗層表面存在尖銳點，這些尖銳點成為電流密度集中點。因此，本論文的主要貢獻是首次提出並採用電化學拋光 (ECP)，通過模擬確定最佳電化學參數，以優先去除這些尖銳點，改善塗層表面的曲率。這隨之減少了Ta/TaN薄膜中的應力集中，提升了製程品質，並通過實驗驗證將失控 (OOC) 發生概率從12.5%降低到2.5%。
;The current mainstream in integrated circuits is the copper (Cu) metal process, such that the interconnects are made of Cu to reduce propagation delays and power consumption. However, due to its high diffusion coefficient, Cu wires tend to form deep energy levels in silicon substrates, leading to degradation in device performance. Additionally, poor adhesion of Cu to dielectric layers severely affects device efficiency. Therefore, research on metallization diffusion barrier layers is needed to overcome the inherent drawbacks of Cu wires. Hence, in semiconductor Cu processes, physical vapor deposition (PVD) of tantalumand /tantalum Nitride (Ta/TaN) multi-layers are of crucial importance, serving as a liner/barrier layer in PVD to prevent diffusion between Cu and silicon (Si) substrates. This study aims to increase the lifespan of PVD chamber kits, reduce particle shedding, and improve process quality. It has practical implications for the semiconductor industry. In practice, Arc spray additively manufactured (ASAM) layers inside the chamber induce surface roughness, enhancing the adhesion of Ta/TaN films. However, peeling occurs when the PVD film reaches a specific thickness, generating particles. Therefore, this study utilizes finite element analysis (FEA) to examine the Ta/TaN multi-layer stress distribution. Simulation results indicate that the leading cause of film peeling is the presence of sharp points on the coating layer surface, which act as points of current density concentration. Consequently, this manuscript′s main contribution is that electrochemical polishing (ECP) is initially proposed and employed, and optimal electrochemical parameters are determined through simulation to preferentially remove these sharp points, improving the curvature of the coating surface. This subsequently reduces stress concentration in the Ta/TaN film, enhances process quality, and is experimentally validated by reducing the probability of out-of-control (OOC) occurrences from 12.5% to 2.5%. |
