Formation of Cu or Cu2O nanoparticles embedded in a polyimide film for nanofloating gate memory.

Cu and Cu2O nanoparticles were fabricated in polyimide by curing the stacked polyamic acid/Cu/polyamic acid on Si wafer and post heat treatment. Nanoparticle distribution in polyimide (a monolayer of vertically aligned nanoparticles or the randomly dispersed nanoparticles) can be controlled by changing the reactivity of Cu with PAA and curing atmosphere. About 6-7 nm sized Cu or Cu2O nanoparticles were observed in the polyimide film. The capacitance-voltage curves were measured with Al/particles in polyimide/p-Si(100) specimens at 300 K, and the capacitance hystereses were observed at different sweep voltage ranges, which indicates that Cu2O or Cu nanoparticles can be utilized in next generation flash memories.