Thermally Assisted Writing of Cells with IrMn Pinning Using 27 Nanosecond Pulses

The very small and dense SDT memory cells arrays can be achieved with SDT memory cells in which the information is stored in the direction of the IrMn low blocking temperature. To demonstrate the durability and stability of the written IrMn antiferromagnetic pinning, a variety of test were conducted. For simplicity in fabrication, the test were conducted with just spin valve cells rather SDT cells. The high speed writing tests were conducted on a variety of spin valve memory cells with 60 Angstrom thick IrMn pinning. Cells were continuously written up to 10 trillion times with 27 nanosecond write pulses at a 9 MHz rate. The amplitude for the pulses was chosen so a single pulse provided sufficient heating or annealing to reverse the pinning. The measured time constant for heating and cooling of the cells was found to be 9+-2 nanoseconds. The tests on the limited number of samples suggests that the cells can be written indefinitely with adequate performance.