Study of TMR with Different Ferromagnetic Material and Variations in Spin-Split, Thickness and Oxide Barrier Height of a MTJ Memory Device

摘要

Due to the scaling problem of conventional non-volatile memory devices such as floating gate and SONOS Flash memories, innovative and improved works are being carried out with an intention to develop a universal memory leading to integrate the speed of SRAM, density of DRAM and non-volatility of Flash memories in a single memory device which can cater to all type of memory requirements. Thus to provide the qualification for portability and power consumption reduction while maintaining a good standard for leakage control and retention time. This paper provides the prospects of STT-RAM with computational study to observe its performance. Fe was found to be a better ferromagnetic material for MTJ devices as compared to the Co. The Tunneling Magneto Resistance (TMR) of the device can be further improved by increasing the width of the 'fixed' ferro-magnetic layer while keeping the width of 'free' ferro-magnetic layer fixed. The TMR increased linearly with the increasing value of oxide barrier height and exponentially with the increasing spin-split of the 'fixed' layer. Fe-Fe3O4-MgO-Fe3O4-Fe and Fe-MgOZnOMgO-Fe MTJ device performance have been studied where we find interesting factors like very high TMR of 1026 for Fe-Fe3O4-MgO-Fe3O4-Fe device but stark contrast of conductance between parallel and anti-parallel orientation is observed.