NANOSTRUCTURAL PROPERTIES OF La2O3/HfO2 GATE DIELECTRICS

There are some issues such as tunneling, leakage currents and boron diffusion through the ultra thin SiO2 which are threatening ultra thin SiO2 dielectric as a good gate dielectric. A very obvious alternative material is HfO2, due to its high dielectric constant, wide band gap and good thermal stability on silicon substrate. We have thus demonstrated a number of processes to synthesize La2O3 /HfO2 and studied its nano structural properties with using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. The obtained results show that La2O3 /HfO2 (at 500 degrees C with amorphous structure) can be introduced as a good gate dielectric for the future of complementary metal insulator semiconductor (CMIS) device.