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

Abstract

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.