Investigation of 1/f noise in germanium-on-insulator 0.12 μm PMOS transistors from weak to strong inversion

This paper presents an experimental analysis of the noise measurements performed in germanium-on-insulator (GeOI) 0.12 μm PMOS transistors from weak to strong inversion. The front gate stack is composed of a HfO2 material with a TiN metal gate (equivalent oxide thickness, EOT, of 1.8 nm). The buried oxide is used as a back gate for experimental purposes. Front gate and back gate oxides/Ge interfaces are characterized. The slow oxide trap densities of the two interfaces are extracted. The values obtained for the front gate oxide are Nt(EFn) = 1.2 × 1018 cm−3 eV−1 and are comparable to values for nitrided oxides on Si bulk. The extracted values for slow oxide trap densities of the BOx SiO2/Ge interface are between 6 and 8 × 1017 cm−3 eV−1 and are close to those of state of art buried oxide SiO2/Si interfaces. These results are of importance for the future development of GeOI technologies.