The effect of IrO₂-IrO₂- Hf-LaAlO₃ gate dielectric on the bias-temperature instability of 3-D GOI CMOSFETs

We have studied the bias-temperature instability of three-dimensional self-aligned metal-gate/high-Κ/Germanium-on-insulator (GOI) CMOSFETs, which were integrated on underlying 0.18 μm CMOSFETs. The devices used IrO₂-IrO₂-Hf dual gates and a high-Κ LaAiO₃ gate dielectric, and gave an equivalent-oxide thickness (EOT) of 1.4 mn. The metal-gate/high-Κ/GOI p-and n-MOSFETs displayed threshold voltage (V^t) shifts of 30 and 21 mV after 10 MV/cm, 85 °C stress for 1 h, comparable with values for the control two-dimensional (2-D) metal-gate/high-Κ-Si CMOSFETs. An extrapolated maximum voltage of - 1.2 and 1.4 V for a ten-year lifetime was obtained from the bias-temperature stress measurements on the GOI CMOSFETs.