Department of Chemical Engineering, National Tsing Hua University, Hsinchu, 30013, Taiwan.
Sci Rep. 2017 Aug 29;7(1):9656. doi: 10.1038/s41598-017-08639-x.
In this study, the effect of 3-2-(2-aminoethylamino) ethylamino propyl trimethoxysilane (ETAS) modification and post rapid thermal annealing (RTA) treatment on the adhesion of electroless plated nickel-phosphorus (ELP Ni-P) film on polyvinyl alcohol-capped palladium nanoclusters (PVA-Pd) catalyzed silicon wafers is systematically investigated. Characterized by pull-off adhesion, atomic force microscopy, X-ray spectroscopy and water contact angle, a time-dependent, three-staged ETAS grafting mechanism including islandish grafting, a self-assembly monolayer (SAM) and multi-layer grafting is proposed and this mechanism is well correlated to the pull-off adhesion of ELP Ni-P film. In the absence of RTA, the highest ELP Ni-P film adhesion occurs when ETAS modification approaches SAM, where insufficient or multi-layer ETAS grafting fails to provide satisfactory results. On the other hand, if RTA is applied, the best ELP Ni-P film adhesion happens when ETAS modification is islandish owing to the formation of nickel silicide, where SAM or multi-layer ETAS modification cannot provide satisfactory adhesion because the interaction between ETAS and PVA-Pd has been sabotaged during RTA. Evidenced by microstructural images, we also confirmed that ETAS can act as an efficient barrier layer for nickel diffusion to bulk silicon.
在这项研究中，系统地研究了 3-2-(2-氨乙基氨基)乙基氨基丙基三甲氧基硅烷（ETAS）修饰和后快速热退火（RTA）处理对聚乙烯醇封端钯纳米簇（PVA-Pd）催化硅片上电沉积镍磷（ELP Ni-P）膜附着力的影响。通过剥离附着力、原子力显微镜、X 射线光谱和水接触角进行了表征，提出了一种时间依赖性的、三阶段的 ETAS 接枝机制，包括岛状接枝、自组装单层（SAM）和多层接枝，该机制与 ELP Ni-P 膜的剥离附着力很好地相关。在没有 RTA 的情况下，当 ETAS 修饰接近 SAM 时，ELP Ni-P 膜的附着力最高，此时不足或多层 ETAS 接枝无法提供满意的结果。另一方面，如果施加 RTA，则当 ETAS 修饰为岛状时，ELP Ni-P 膜的附着力最佳，这是因为形成了镍硅化物，而 SAM 或多层 ETAS 修饰不能提供满意的附着力，因为在 RTA 过程中，ETAS 和 PVA-Pd 之间的相互作用已被破坏。通过微观结构图像，我们还证实了 ETAS 可以作为镍向体硅扩散的有效阻挡层。
