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Low-frequency noise measurements were performed on p- and n-channel MOSFETs with HfO2, HfAlOx and HfO2/Al2O3 as the gate dielectric materials. The gate length varied from 0.135 to 0.36 μm with 10.02 μm gate width. The equivalent oxide thicknesses were: HfO2 23 Å, HfAlOx 28.5 Å and HfO2/Al2O3 33 Å. In addition to the core structures with only about 10 Å of oxide between the high-κ dielectric and silicon substrate, there were "double-gate oxide" structures where an interfacial oxide layer of 40 Å was grown between the high-κ dielectric and Si. DC analysis showed low gate leakage currents in the order of 10-12A(2-5×10-5 A/cm2) for the devices and, in general, yielded higher threshold voltages and lower mobility values when compared to the corresponding SiO2 devices. The unified number-mobility fluctuation model was used to account for the observed 1/f noise and to extract the oxide trap density, which ranged from 1.8×1017 cm-3eV-1 to 1.3×1019 cm-3eV-1, somewhat higher compared to conventional SiO2 MOSFETs with the similar device dimensions. There was no evidence of single electron switching events or random telegraph signals. The aim of this paper is to present a general discussion on low-frequency noise characteristics of the three different high-κ/gate stacks, relative comparison among them and to the Si--SiO2 system.