Patent ID: 8908425
Filing Date: 2014-12-09
Classification: G11C,Y10S

Abstract:
1. A method for writing to a thermally assisted magnetoresistive random access memory (MRAM) device, the method comprising: applying a write current to heat the MRAM device to a write temperature; wherein the MRAM device comprises an antiferromagnetic layer and a synthetic antiferromagnetic layer disposed on the antiferromagnetic layer, the synthetic antiferromagnetic layer comprising a first ferromagnetic storage layer, a non-magnetic coupling layer disposed on the first ferromagnetic storage layer, and a second ferromagnetic storage layer disposed on the non-magnetic coupling layer; wherein the MRAM device further comprises a non-magnetic tunnel barrier disposed on the second ferromagnetic storage layer and a ferromagnetic sense layer disposed on the non-magnetic tunnel barrier; demagnetizing respective ferromagnetisms in the second ferromagnetic storage layer and the ferromagnetic sense layer from the heat, resulting in reduced stray magnetic fields; applying a write field that interacts with ferromagnetism of the first ferromagnetic storage layer, the write field switching a first magnetic orientation of the first ferromagnetic storage layer, wherein the ferromagnetism of the first ferromagnetic storage layer is not demagnetized by the heat at the write temperature; wherein when the write current is removed to cool the MRAM device below the write temperature, exchange bias of the first ferromagnetic storage layer switches a second magnetic orientation of the second ferromagnetic storage layer according to the first magnetic orientation of the first ferromagnetic storage layer previously switched.