In this work we evaluate the impact of the gate stack layers deposition technologies and their combination on the thermal stability of the stack with respect to EOT vs leakage figure of merit. Two HfO2 deposition technologies have been used: ALCVD and AVD (for Atomic Vapor Deposition); and two TiN deposition technologies have been evaluated: CVD and PVD. As a result, it appears that stack stability after a 1050 °C spike anneal can be achieved by combination of AVD HfO2 and PVD TiN. Anyway a trade-off in terms of mobility degradation using this metallic layer deposition technique is still present.