Size‐Controlled Colloidal Pd(II) Catalysts for Electroless Ni Deposition in Nanolithography Applications
Size‐Controlled Colloidal Pd(II) Catalysts for Electroless Ni Deposition in Nanolithography Applications
复制标题
DOI：
10.1149/1.1838028
复制
发表时间：
1997-10
影响因子：
3.9
通讯作者：
S. Brandow;Mu‐San Chen;Tina Wang;C. Dulcey;J. Calvert;J. F. Bohland;G. S. Calabrese;W. Dressick
中科院分区：
文献类型：
--
作者：
S. Brandow;Mu‐San Chen;Tina Wang;C. Dulcey;J. Calvert;J. F. Bohland;G. S. Calabrese;W. Dressick
一种新的Pd（Ⅱ）无电金属沉积催化剂分散体，PD 2，通过淬火的PdCl 4 2溶液与HCl和过量的NaCl，然后快速水解，在pH = 7和0.8 mM NaCl的描述。通过X射线光电子能谱、紫外-可见光谱、离心和化学测试，显示催化Pd（0）物种的前体是具有负表面电荷的富含氯化物的Pd（II）胶体颗粒。颗粒选择性地和共价地结合在配体修饰的表面上，处理时间≥2分钟即可实现完全表面覆盖。原子力显微镜表明，结合颗粒的平均尺寸和最大尺寸分别为9 ± 3和18 nm。在催化表面金属化之后，获得平均尺寸为21 ± 5 nm的Ni颗粒的相应窄分布（15至33 nm）。使用PD 2控制Ni颗粒形态的能力被成功地利用在通过扫描隧道显微镜图案化的15 nm特征的选择性金属化中。金属化发生时，特征几何形状的变形最小，并且没有由于Ni过度生长或相邻特征的桥接而导致的图案退化。催化剂的行为是很好地描述了一个模型，其中颗粒成核事件和分散介质化学在胶体形成过程中决定颗粒表面结合，稳定性，大小和分散性的支配
A new Pd(II) electroless metal deposition catalyst dispersion, PD2, prepared by quenching a PdCl 4 2 solution with HCl and excess NaCl following rapid hydrolysis at pH ∼ 7 and ∼0.8 mM NaCl is described. The precursors to the catalytic Pd(0) species are shown to be chloride-rich Pd(II) colloidal particles having negative surface charge by x-ray photoelectron spectroscopy, UV-visible spectroscopy, centrifugation, and chemical tests. The particles bind selectively and covalently at ligand-modified surfaces with complete surface coverage occurring for treatment times ≥2 min. Atomic force microscopy indicates that the average and maximum sizes of the bound particles are 9 ± 3 and 18 nm, respectively. A correspondingly narrow distribution (15 to 33 nm) of Ni particles of average size 21 ± 5 nm is obtained following metallization of catalyzed surfaces. The ability to control Ni particle morphology using PD2 is successfully exploited in the selective metallization of ∼15 nm features patterned by scanning tunneling microscopy. Metallization occurs with minimal distortion of feature geometries and no pattern degradation due to Ni overgrowth or bridging of adjacent features. Catalyst behavior is well described by a model in which domination of particle nucleation events and dispersion medium chemistry during colloid formation determine particle surface binding, stability, size, and dispersity