Buttiker Probe Based Modeling of TDDB: Application to Dielectric Breakdown in MTJs and MOS Devices

Abstract

Dielectric layers are gradually being down-scaled in different electronic devices like MOSFETs and Magnetic Tunnel Junctions (MTJ) with shrinking device sizes. As a result, time dependent dielectric breakdown (TDDB) has become a major issue in such devices. In this paper we propose a generalized way of modeling the stress induced leakage current (SILC) and post breakdown current (PBC) due to time dependent wear-out of the dielectric layer. We model the traps formed in dielectric layer using Buttiker probe and incorporate the Buttiker probe self-energies in standard self-consistent Non-Equilibrium Green Function (NEGF) formalism in order to determine SILC and PBC. In addition, we have shown the impact of break down in the dielectric layer on the spin current and spin filtering characteristics of an MTJ. The proposed model is generic in nature. It can be extended from MTJs and conventional CMOS technology to any other devices with any type of single and multiple layers of dielectric material(s).