Abstract: Nickel fully silicided (Ni-FUSI) gate material has been fabricated on a HfO₂ surface to form a Ni-FUSI gate/HfO₂/Si/Al (MIS) structure by using an ultra-high vacuum e-beam evaporation (EBV) method followed by a one step rapid thermal annealing (RTA) treatment. X-ray diffraction (XRD) and Raman spectroscopy were used to reveal the microstructures and electrical properties of the MIS structure. Results show that a one step post RTA treatment is enough to promote the full reaction of nickel silicide, compared with multiple RTA treatments. Furthermore, the HfO₂ gate dielectric film is sensitive to heat treatment, and multiple RTA treatments can damage the electrical properties of the HfO₂ film rather than improve them. By optimization of the sample fabrication technique, the MIS capacitor produces good high-frequency capacitance-voltage curves with a hysteresis of 30 mV, a work function of about 5.44-5.53 eV and leakage current density of only 1.45 × 10^-8 A/cm² at -1 V gate bias.

Key words: Ni-FUSI gate