Cell Structure. A material with perpendicular magnetic anisotropy, which is used for recording media and a type of cobalt-iron, is employed in the magnetic layer, with magnesium oxide in the insulating layer and cobalt-iron-boron in the interface layers. Credit: Toshiba
Toshiba applied and proved the spin transfer switching and perpendicular magnetic anisotropy (PMA) technologies in a magnetic tunnel junction, which is a key component in the memory cell.
Spin transfer switching uses the properties of electron spin to invert magnetization and writes data at very low power levels. It is widely regarded as a major candidate among next-generation principles for new memory devices. PMA aligns magnetization in the magnetic layer perpendicularly, either upward or downward, rather than horizontally as in in-plane shape anisotropy layers.
The technology is being increasingly used to enhance for storage capacity for high-density hard disc drives (HDDs), and Toshiba has successfully applied it to a semiconductor memory device. With PMA data write operation and magnetic switching can be achieved at a low energy level. Toshiba also overcame the hurdle of achieving the required precision in the interface process and significantly cutting write power consumption.
In order to realize a miniature memory cell based on PMA, Toshiba optimized the materials and device structure of the new MRAM.