Temperature Increase Due to Joule Heating in a Nanostructured MgO-Based Magnetic Tunnel Junction Over a Wide Current-Pulse Range

Abstract

The temperature increase due to Joule heating in a nanopillar of a magnetic tunnel junction sandwiched by top and bottom electrodes was calculated by the finite element method. The results for the critical condition for the current-induced magnetization switching measured over a wide current-pulse range were taken from the literature. At long pulse widths, the temperature increase was solely dependent on the magnitude of the critical current density. However, no saturation in the temperature increase occurred for short pulse widths. In this case, the temperature increase additionally depended on the pulse width, so that a broad maximum occurred in the pulse width (or the critical current density) dependence of the temperature increase. The original results for the critical condition were corrected by accounting for the temperature increase and these corrected results, together with the Slonczewski equation, were used to extract an accurate value for the thermal stability factor.

Time-dependent dielectric breakdown of MgO magnetic tunnel junctions and novel test method

“…Because the heat generated by selfheating in MTJs affects TDDB, we used a temperature of 120 °C for the MTJs in our experiments. [26][27][28][29][30] In order to realize STT-MRAM, a low RA is required. Therefore, to achieve a low RA and make predictions regarding the MTJ with a 1.0 nm MgO tunnel barrier, we fabricated MTJ samples that have MgO tunnel barrier thicknesses of 1.1 and 1.2 nm.…”