Current aspects and future perspectives of high-density MRAM

Magnetoresistive random access memory (MRAM) is regarded as one of the leading candidates for universal memory [1] that will be commercialized in the foreseeable future. The figure of merits for MRAM technology includes non-volatility, high speed, high density, radiation hardness, and unlimited endurance. Very promising R & D results have been announced wordlwide. For a high density MRAM as a stand-alone memory, uniform resistance and switching control for sub-micron and deep sub-micron devices must be guaranteed. To achieve this goal, several material and device issues related with MRAM core cell should be resolved. Resistance (R) as well as magnetoresistance (MR) are limited by the uniformity of barrier thickness induced by bottom electrode. Switching issues appear controllable with a choice of appropriate shape and fine patterning process.