The scaling down of complementary metal-oxide-semiconductor (CMOS) devices in microelectronics needs nowadays a sub-1 nm equivalent oxide thickness (EOT, see Eq. 1.4) gate dielectric to meet the requirements of shrinking to deep sub-micron dimensions. The investigated high-κ dielectrics include ZrO2, ZrSiO4, HfO2, HfSiO4 as well as rare earth oxides that form one of the most interesting groups for both MOS and MIM applications. 1 However, no clear candidate to replace SiO2 has definitively emerged and a lot of inconveniences related to the material deposition, stability and electrical performances are still unresolved. In particular, the reliability of the high-κ dielectrics is a quite important issue though not so many data or insight in the physical mechanisms have been proposed to date. 2, 3 Gate insulator degradation and breakdown (BD) are critical problems in ultra large scale integration (ULSI) of CMOS …