Electrical Properties of Ferroelectric BaMgF4 Films on Si Substrates

Abstract
Electrical properties of (120)-oriented BaMgF4 films grown on n-Si(111) substrates have been investigated. It has been found that capacitance-voltage (C-V) characteristics of Al/ BaMgF4(120)/n-Si(111) structures show hysteresis loops with counterclockwise traces and that the memory window (the loop width) is proportional to the magnitude of the voltage applied to the film. It is speculated from these phenomena that the hysteresis loop is caused by remanent polarization of the BaMgF4 film. The value of the surface charge density, which was estimated from the memory window, was about 0.1 µ C/cm2 in a 330-nm-thick BaMgF4 film. It has also been found from C-V and current-voltage characteristics that typical dielectric constant and average resistivity of BaMgF4 films are 9.4 at 5 kHz and 3.6×1011 Ω· cm at a current density of 1 µ A/cm2, respectively.