Evolution of the Physics and Stochastics of Failure in Ultra-Thin Dielectrics - From SiO2 to Advanced High-K Gate Stacks

Dielectric breakdown in logic devices has been a subject of intense study for several decades. With changing dielectric thickness due to downscaling of complementary metal oxide semiconductor (CMOS) technology as well as the shift from SiO₂ to other high permittivity dielectric materials, there is a noteworthy change in the physics of failure and the statistical trend of soft, progressive and hard breakdown in oxide films. This study presents a brief summary comparing the physical mechanisms of breakdown and associated stochastics of the failure time distribution in SiO₂ and high-κ (HfO₂). It is clearly evident that there is a continuous need for more research into oxide breakdown, given the shift towards 2D layered dielectrics such as hexagonal boron nitride in the near future, with markedly different breakdown dynamics.