Mesoscopic approach to progressive breakdown in ultrathin SiO<inf>2</inf> layers

The opening of a breakdown path across the ultrathin oxide layer in a metal-oxide-semiconductor structure caused by the application of electrical stress can be analyzed within the framework of the physics of mesoscopic conductors. Using the Landauer formula for a quantum point contact, the author is able to show that the saturation of the gate leakage current is linked to the progressive evolution of the constriction's conductance toward the ballistic transport regime. The possible physical mechanisms responsible for energy dissipation inside the breakdown path as well as the limitations of the proposed approach are discussed. © 2007 American Institute of Physics.