Department of Materials Science and Engineering, University of Texas at Dallas, 800 West Campbell Road, RL 10, Richardson, Texas 75080, United States.
Langmuir. 2011 Jun 7;27(11):6932-9. doi: 10.1021/la2012843. Epub 2011 May 9.
We have investigated the seedless electroless deposition (ELD) of Ni on functionalized self-assembled monolayers (SAMs) using scanning electron and optical microscopies, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry. For all SAMs studied, the Ni deposition rate is dependent on the bath pH, deposition temperature, and complexing agent. In contrast to the physical vapor deposition of Ni on SAMs, electrolessly deposited Ni does not penetrate through the SAM. This behavior indicates that ELD is a suitable technique for the deposition of low-to-moderate reactivity on organic thin films. We demonstrate that Ni can be selectively deposited on SAMs using two different methods. First, selectivity can be imparted by the formation of Ni(II)-surface complexes. As a demonstration, we selectively deposited Ni on the -COOH terminated SAM areas of patterned -COOH/-CH(3) or -COOH/-OH terminated SAMs. Here, Ni(2+) ions form Ni(2+)-carboxylate complexes with the -COOH terminal group, which comprise the nucleation sites for subsequent metal deposition. Second, we demonstrate that nickel is selectively deposited on the -CH(3) terminated SAM areas of a patterned -OH/-CH(3) terminated SAM. In this case, the Ni(2+) ion does not specifically interact with the -CH(3) terminal group. Rather, selectivity is imparted by the interaction of the reductant, dimethylamine borane (DMAB), with the -OH and -CH(3) terminal groups.
我们使用扫描电子显微镜和光学显微镜、X 射线光电子能谱和飞行时间二次离子质谱研究了功能化自组装单层（SAM）上无种子化学镀镍（ELD）。对于所有研究的 SAM，镍沉积速率取决于镀液 pH、沉积温度和络合剂。与 SAM 上 Ni 的物理气相沉积相反，化学镀 Ni 不会穿透 SAM。这种行为表明 ELD 是在有机薄膜上沉积低至中等反应性的合适技术。我们证明可以使用两种不同的方法选择性地在 SAM 上沉积 Ni。首先，可以通过形成 Ni(II)-表面络合物赋予选择性。作为一个演示，我们选择性地在图案化的-COOH/-CH(3)或-COOH/-OH 终止的 SAM 上的-COOH 终止 SAM 区域上沉积 Ni。在这里，Ni(2+) 离子与-COOH 端基形成 Ni(2+)-羧酸盐配合物，后者构成随后金属沉积的成核位点。其次，我们证明镍选择性地沉积在图案化的-OH/-CH(3)终止的 SAM 上的-CH(3)终止 SAM 区域上。在这种情况下，Ni(2+) 离子不会与-CH(3)端基特异性相互作用。相反，选择性是由还原剂二甲胺硼烷（DMAB）与-OH 和-CH(3)端基的相互作用赋予的。
