No abstract

In this study, the influence of thermal budget on preparing hafnium silicate (HfSiO) and metal–insulator–semiconductor (MIS) structures with tetragonal hafnium oxide (HfO2) films was investigated. Amorphous silicon (a-Si) was used as a sacrificial layer for HfSiO formation. Rapid thermal annealing (RTA) could efficiently drive the oxidation of a-Si with HfO2. The RTA-produced HfSiO film thicker than that produced through furnace annealing could suppress gate leakage in MIS devices, and aid in maintaining a high dielectric constant of the gate insulator. The combination of sacrificial a-Si film use and RTA application resulted in a HfSiO/HfO2 structure (named as hybrid HfO2), which demonstrated a high dielectric constant and strength (29.5 and 21.2 MV cm−1, respectively). MIS devices integrated with this hybrid HfO2 achieved a hysteresis value of only 0.11 V on a flat-band voltage measured at a 50 mV s−1 sweep rate with an applied voltage between −5 and 5 V.