Performance of write-line inserted magnetic tunneling junction for low-write-current magnetic random access memory cell

We have developed a write-line-inserted magnetic tunneling junction (MTJ) (WLIM) for use in low-write-current magnetoresistance random access memory (MRAM). The write current of the WLIM was reduced to 0.98mA and its thermal stability factor was 85 for a 0.32×0.48μm2 MTJ. We evaluated the switching property of the WLIM in an external magnetic field (Hsw̱ext) and an internal magnetic field (Hsw̱int). We found that Hsw̱ext was larger than Hsw̱int when the aspect ratio of the MTJs was less than 1.5. Furthermore, we obtained a high write-current magnetic-field efficiency of 13.0Oe∕mA when the aspect ratio of the MTJs was low. These properties mean that the WLIM structure has advantages for use in low-write-current MRAM.