The potential barrier and thermal stability dependence on PI thickness of AL/PI/C-SI schottky diode

Abstract

This research investigated the effectiveness of using different thickness values of polyimide (PI) interfacial layer in order to improve electrical and thermal properties of Al/ PI /c-Si capacitor. The PI spectra produced by poly(amic acid) (PAA) were characterized by using FT-IR analysis. After imidization of PAA, some absorption peaks vanished, whereas PI peaks appeared, due to the complete conversion of PAA to PI. The dependence of current -voltage and Capacitance-Voltage characteristics of Al/PI/c-Si on PI thickness (10, 20, 30, 40 nm) was exhibited through the increase of potential barrier and built-in potential and the decrease of the saturation current. These results may be interpreted in terms of the decrease in the interfacial defects, such as surface states and interface defects, which leads to reduce the potential barrier between Aluminum and crystalline Silicon and increase saturation current. The results show that thermal decomposition resistance of polyimide films increases with the increase of polyimide thickness, because of the increase of the imide bond and the decrease of the average distance between amide groups.