High Speed MRAM Using Giant Magnetoresistance

Using newly discovered Giant Magnetoresistance Ratio (GMR) materials, a Magnetoresistive Random Access Memory (MRAM) will be designed which is speed competitive with and denser than semiconductor Static RAM. The higher GMRs of 6% to 8% compared with 2% magnetoresistance for previously used materials will result in a 10 fold or more improvement in MRAM read access time. These GMR materials give an additional significant advantage in area because they have two to three times higher sheet resistivities. Memory circuit architectures, modes of operation and other design considerations for MRAM using these GMR materials will be explored in Phase I, and a GMR memory cell will be demonstrated which circuit simulations will show to be suitable for a 256Kbit MRAM with an access time of 20ns to 40ns. A memory array architecture will be designed around this GMR memory cell and simulated. An MRAM chip will be designed and built using this architecture in Phase II. Industrial, military, and space markets for high speed R/W memory where nonvolatility and radiation hardness are desired are the most likely first users of results of this program.