Electrical characterization of gadolinium oxide deposited by high pressure sputtering with in situ plasma oxidation

Abstract

In this work, we characterized gadolinium oxide films deposited on silicon by high pressure sputtering with a two-step process: first, we sputtered metallic gadolinium in an argon atmosphere and then, we performed an in situ plasma oxidation of the metallic layer previously deposited. By means of high resolution transmission electron microscopy, we can detect the oxidation degree of the metallic film. Under optimized deposition conditions, fully oxidized Gd2O3 films are obtained. In addition, the capacitance and conductance as a function of gate voltage of Pt gated metal–insulator–semiconductor capacitors confirm stable dielectric behavior of the fully oxidized films. The devices show low gate leakage currents (∼10−5 A/cm2 at 1 V for 2.2 nm of equivalent oxide thickness), low interface trap density and an almost negligible hysteresis and frequency dispersion.