Electrostatic force microscopy analysis of Bi0.7Dy0.3FeO3 thin films prepared by pulsed laser deposition integrated with ZnO films for microelectromechanical systems and memory applications

Abstract

In this paper, we report the charge trapping phenomena in zinc oxide (n-ZnO) and Bi0.7Dy0.3FeO3 (BDFO)/ZnO thin films deposited on p-type <100> conducting Si substrate. The significant change in contrast above the protrusions of ZnO verifies the possibility of heavy accumulation of injected holes in there. The ZnO and BDFO/ZnO films were characterized by the electrostatic force microscopy (EFM) to understand the phase dependence phenomenon on the bias supporting electron tunnelling. The EFM has an important role in the analysis of electrical transport mechanism characterization and electric charge distribution of local surface in nanoscale devices. It was observed that in BDFO/ZnO, the contrast of EFM images remains constant with the bias switching and that primarily indicates availability of trap sites to host electrons. The change in contrast over the protrusions of ZnO suggests that mobility of the electrical charge carriers may be through the grain boundary. The formation of these hole-trapped sites may be assumed by bond breaking phenomenon.