Study on the Electrical Conduction Mechanism in Al2O3/Polyimide Langmuir-Blodgett Film Systems

Abstract

We fabricated Al/Al₂O₃/polyimide Langmuir-Blodgett films (PI LB)/Al (MIM) and Al/Al₂O₃/PI LB/Al/Al₂O₃/PI LB/Al (MIMIM) junctions by means of the LB technique, and then examined the electrical transport properties of the junctions from the tan δ values of these junctions. For MIM junctions, the tunneling conduction mechanism dominated in PI LB films when the number of deposited PI LB films was less than 4. In contrast, the bulk conduction mechanism dominated when the number of deposited PI LB films was greater than 5. For MIMIM junctions, the tan δ value of the junctions was about 10% of that of MIM-external wire-MIM junctions. It was concluded that middle Al/Al₂O₃ layers sandwiched between top Al and base Al electrodes control the number of electrons passing through MIMIM junctions.