Consideration of optimum resistance values of MTJ in multilayered MRAM with various detection methods

For each case of current and voltage detection in series connections, and current and voltage in parallel connections in the multi-layered structure of a magnetoresistive random access memory (MRAM) cell having two serially connected magnetic tunnel junction (MTJ) layers, first, we demonstrate the existence of an optimum value for the weighting coefficient k of the resistance, the voltage dependence, and the dependence on the magnetic resistance (MR) of the MTJ. Therefore, to optimize the signal margin in multiple layers, the ability to detect series connections with high sensitivity up to an MR ratio of 1 is demonstrated quantitatively. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(3): 42–48, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20265