Synthesis and film deposition of Ni nanoparticles for base metal electrode applications

This paper describes the preparation of Ni thin films for base metal electrode applications using Ni nanoparticles that were synthesized by thermal decomposition of a Ni–oleate complex under inert gas flow. The oleate molecules both retarded particle growth and prevented oxidation. The mean particle sizes of the cubic phase Ni nanoparticles synthesized at decomposition temperatures of 350, 380, and 400 °C were 5.1, 5.5, and 6.6 nm, respectively. The average activation energy for Ni nanoparticle formation was 157.51 ± 13 kJ mol−1, revealing a single kinetic mechanism. After formulation of a moveable paste, the Ni nanoparticles were well-dispersed on a silicon wafer using a spin coater. The deposited Ni films were further investigated for sintering behavior. Based on the cross-sectional images, the thickness of the as-deposited Ni film was 2.5 μm, while the film sintered at 800 °C was 1-μm thick. The sintered Ni films had a high continuity, without any cracks or voids. The bulk resistivity of the Ni film sintered at 800 °C was 1.8 × 10−5 Ω cm.