Title :
Micro magnetic simulation of write error probability in STT-MRAM
Author :
Kawabata, K. ; Tanizawa, M. ; Ishikawa, K. ; Inoue, Y.
Author_Institution :
Renesas Technol. Corp., Itami
Abstract :
STT MRAM is one of the most promising candidates for the next generation non-volatile memory. The STT-MRAM write operation is to switch the magnetization direction of ferromagnetic free layer with spin transfer torque by current injection. A ferromagnetic thin film used in it is so small volume that the thermal fluctuation due to ambient temperature has to be considered in the device design. Its process is described by a stochastic probability distribution. In this paper, a write error probability function in STT MRAM at finite temperature is investigated based on the result of LLG micro magnetic simulation. The function is found to be a Weibull type function with modulus, beta. The physical meanings of beta is found to be an index of competitions between thermal activation process and spin transfer torque ones in switching of STT MRAM at finite temperature.
Keywords :
MRAM devices; error statistics; magnetisation; micromagnetics; thin films; torque; STT-MRAM; Weibull type function; current injection; ferromagnetic free layer; ferromagnetic thin film; magnetization direction; micromagnetic simulation; next generation nonvolatile memory; spin transfer torque; stochastic probability distribution; thermal activation process; thermal fluctuation; write error probability; write operation; Error probability; Fluctuations; Magnetic switching; Magnetization; Nonvolatile memory; Stochastic processes; Switches; Temperature; Thin film devices; Torque; MRAM; finite temperature switching process; spin transfer torque;
Conference_Titel :
Simulation of Semiconductor Processes and Devices, 2008. SISPAD 2008. International Conference on
Conference_Location :
Hakone
Print_ISBN :
978-1-4244-1753-7
DOI :
10.1109/SISPAD.2008.4648235
