Charging and discharging processes in ALN dielectric films deposited by plasma assisted molecular beam epitaxy

In the present work the electrical properties of AlN polycrystalline films deposited at low temperatures by plasma-assisted molecular beam epitaxy (PA-MBE) are investigated. The polarization build-up during constant current injection as well as the depolarization process after the current stress have been investigated through monitoring voltage transients in Metal-Insulator-Metal (MIM) capacitors, in temperature range from 300 K to 400 K. Moreover, current-voltage characteristics obtained at different temperatures revealed that charge collection at low fields in these films occurs through variable range hopping.