The increasing of gate leakages current, caused by direct tunneling in ultra oxide films, is the crucial factor eliminating conventional SiO2-based gate oxide in sub-90 nm CMOS technology development. In this work, we use hafnium oxide as MOS dielectric when the gate length is 90 nm, and compare the high-k material with SiO2 in different electrical characters, such as capacitance-voltage (C-V), current-voltage (I-V) measurement. This work used ISE-TCAD to simulate CMOS devices. We use high dielectric constant in replacing SiO2 as the gate oxide, and change the gate oxide thickness to know the different characters.
