Structural and electrical characteristics of Er2 Ti O5 gate dielectrics

The authors report on the structural and electrical characteristics of high- k erbium titanium oxide (Er2 Ti O5) gate dielectrics deposited on Si (100) substrates by reactive rf sputtering. They find that the capacitance value of Er2 Ti O5 gate dielectric annealed at 700 °C is higher compared to other annealing temperatures and exhibits a lower hysteresis voltage as well as interface trap density in C-V curves. This dielectric also shows almost negligible charge trapping under high constant voltage stress. This phenomenon is attributed to an amorphous Er2 Ti O5 structure and the suppression of the interfacial layer and Er silicate observed from x-ray diffraction and x-ray photoelectron spectroscopy, respectively.