Two Different Approaches to the Fabrication of Nano-Sized Particles in Thick Polyimide Films

Abstract

Relatively thick polyimide films (> 800 inn) containing copper-based nanoparticles were fabricated via two different methods: a multiple-stacking method and a concentrated polyamic acid (PAA) method. For the multiple-stacking samples, we repeated the stacking of 2.5 wt% PAA and 4 rim thick Cu thin film structures and then thermally cured the stacked samples. In the case of the concentrated PAA samples, the concentrated PAA (10 wt%) was spin-coated on the 10 nm and 25 nm thick Cu thin films and thermally cured. The phase and distribution of nanoparticles fabricated by both methods were characterized by X-ray diffraction and transmission electron microscopy. The fabricated nanoparticles were dispersed in thick polyimide films and the size of the nanoparticles was sensitive to the amount of metal sources. The nanoparticles dispersed in the thick polyimide film had two different phases: the metallic copper phase and the cuprous oxide phase. Enhanced surface plasmon resonance absorption was observed in the metallic Cu nanoparticles.