Effect of Self-Heating on Time-Dependent Dielectric Breakdown in Ultrathin MgO Magnetic Tunnel Junctions for Spin Torque Transfer Switching Magnetic Random Access Memory

Abstract

Spin torque transfer switching magnetic random access memory (Spin-MRAM) using MgO-magnetic tunnel junction (MTJ) is considered to be the most promising candidate for high-density, high-speed, and non-volatile RAM. Notwithstanding its excellent potential, the breakdown mechanism of MgO-MTJ has not been well understood although a thorough understanding is essential for commercialization of Spin-MRAM. In this paper, we demonstrate for the first time the modeling of dielectric breakdown phenomena of MgO-MTJ by time-dependent dielectric breakdown (TDDB) measurement concerning the effect of self-heating using simulation and conclude that E-model with the effect of self-heating at MgO-MTJ during current stress (power) removed gives the best fitting as a degradation model of MgO-MTJ ultrathin dielectrics.