Temperature and pH dependence of the electroless Ni–P deposition on silicon

• Published in: Thin solid films Vol. 510; no. 1; pp. 102 - 106
• Main Authors: Liu, W.L., Hsieh, S.H., Tsai, T.K., Chen, W.J., Wu, Shin Shyan
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 03.07.2006; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Electroless deposition; Electron and ion emission by liquids and solids; impact phenomena; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Field emission, ionization, evaporation, and desorption; General studies of phase transitions; Nickel; Nucleation; Physics; Scanning electron microscopy; Scanning electron microscopy; Nickel; Electroless deposition; Temperature dependence; Atomic force microscopy; Particle size; Inorganic compounds; Nucleation; Thick films; Polycrystals; Experimental study; Field emission electron microscopy; Columnar structure; Growth kinetic; Transmission electron microscopy; Growth mechanism; Crystal growth from solutions; Electrodeposition; Activation energy
• DOI: 10.1016/j.tsf.2005.12.203
• ISSN: 0040-6090

The sensitization, activation, nucleation and growth of electroless Ni–P deposition on silicon in an acid plating bath with sodium hydrophosphite as reducing agent and sodium succinate as complexing agent were studied by transmission electron microscopy, field emission scanning electron microscopy and atomic force microscopy. The results show that a continuous polycrystalline SnCl 2 film was formed on the silicon surface in the sensitization process, and small crystalline Pd particles were dispersedly produced on SnCl 2 film in the activation process. In the initial deposition stage, the small Ni–P particles had already emerged on the silicon surface in a deposition time of less than 2 s. When Ni–P particles grew, their size increased but their number decreased, and they later developed into a columnar structure. The deposition rate of the electroless Ni–P deposit increased as the pH value and the temperature of the plating bath increased (from 1.36 to 29.66 μm/h). The activation energy of the electroless Ni–P deposition on silicon increased as the pH value of the plating bath decreased (from 68.8 to 79.4 kJ/mol).