Different Effect of Temperature Increment on CoFeB/MgO Based Single and Double Barrier Magnetic Tunnel Junctions during Switching Process in STT-MRAM

Abstract

Recently, double barrier magnetic tunnel junction (DBMTJ) can be applied for spin transfer torque magnetic random access memory (STT-MARM) technology. DBMTJ provides a higher thermal stability factor and a lower critical current when comparing with the single barrier magnetic tunnel junction (SBMTJ). However, the double MgO layers in structure can affect the high temperature during switch process. Therefore, this work explored the different effect of temperature increment on both SBMTJ and DBMTJ during the switching current flow. Structures for study consist of the SBMTJ with MgO thickness of 0.9 nm, the DBMTJ with MgO thickness of 0.9 nm (DBMTJ(A)) and the DBMTJ with MgO thickness of 1.3 nm (DBMTJ(B)). Simulation can be achieved by 3D finite element method. The results show that although the DBMTJ(B) has the minimum critical current when comparing with DBMTJ(A) and SBMTJ, the maximum temperature increment is found with DBMTJ(B) at the same switching current in the switching process. Hence, the thermal reliability of DBMTJ device applied for in-plane MTJ in STT-MRAM is interesting for improvement of the memory technology.