Lanthanum Lutetium oxide integration in a gate-first process on SOI MOSFETs

The chemical reactions at the higher-k LaLuO₃/Ti₁N_X/poly-Si gate stack interfaces are studied after high temperature treatment. A Ti-rich TiN metal layer degrades the gate stack performance after high temperature annealing. The gate stack containing TiN/LaLuO₃ with a near stoichiometric TiN layer is stable during 1000 °C, 5s anneals. Both electrical and structural characterization methods are employed to explore the thermal stability of the gate stack. Based on these results an integration of TiN/LaLuO₃ in a gatefirst MOSFET process on SOI is shown.