Effects of curing time on the Cu oxide nanoparticles formation

Abstract

Recently, we have studied metal oxide nanoparticle formation in a polyimide (PI) film. Polyamic acid (PAA) was spin-coated onto Cu thin films and PAA/metal films were cured at 350℃. In this paper, we investigated the effects of holding time during curing on the Cu oxide nanoparticles formation. A thin layer of polyimide precursor, polyamic acid (PAA) was spincoated on the 5-10 nm thick copper then the film stacks were baked at 135℃ for 30 min to remove the solvent and thermally cured in N2 atmosphere at 350℃. The holding time were 1, 2, or 4 hours at 350℃. The size and distribution of Cu oxide particles were characterized using Transmission Electron Microscope (TEM). Cubic Cu2O formation in the polyimide film was confirmed by Selected Area Diffraction pattern (SAD) pattern analysis. The degree of imidization of PI was characterized by FTIR spectrometer. Very uniform and dense Cu2O particles of 5 nm could be fabricated by controlling holding time during curing