Influence of Annealing Atmosphere on the Electrical Conductivity of Copper Nanoparticle Films

Influence of Annealing Atmosphere on the Electrical Conductivity of Copper Nanoparticle Films

The oxidation, organic decomposition, and grain growth of Cunanoparticles were systematically investigated under various heattreatmentconditions to understand the correlation between the heattreatmentcondition and the electrical conductivity of nanoparticlebasedcopper films. The resistivity of Cu films annealed at 400°C inN2 gas was ~3 × 102 μΩ·cm, which is two orders lower than that of aCu film annealed in a reducing gas (~104μΩ·cm). The lowestresistivity of 9 μΩ·cm was achieved at an annealing temperature of600°C in N2 gas. The N2 atmosphere containing a fairly small amountof O2 was found to remove residual organics easily and facilitate thegrain growth of Cu nanoparticles, thereby yielding Cu films withsuperior electrical conductivity. These results clearly demonstrate theimportance of precise control of oxygen during the annealing process.

The oxidation, organic decomposition, and grain growth of Cunanoparticles were systematically investigated under various heattreatmentconditions to understand the correlation between the heattreatmentcondition and the electrical conductivity of nanoparticlebasedcopper films. The resistivity of Cu films annealed at 400°C inN2 gas was ~3 × 102 μΩ·cm, which is two orders lower than that of aCu film annealed in a reducing gas (~104μΩ·cm). The lowestresistivity of 9 μΩ·cm was achieved at an annealing temperature of600°C in N2 gas. The N2 atmosphere containing a fairly small amountof O2 was found to remove residual organics easily and facilitate thegrain growth of Cu nanoparticles, thereby yielding Cu films withsuperior electrical conductivity. These results clearly demonstrate theimportance of precise control of oxygen during the annealing process.