Patent ID: 7881099
Filing Date: 2011-02-01
Classification: B82Y,G11C,H01F,H01L

Abstract:
1. A writing method for a magnetic memory comprising a memory cell comprising at least first and second magnetically changeable ferromagnetic layers, and a ferromagnetic reference layer, the first magnetically changeable ferromagnetic layer being disposed on the second magnetically changeable ferromagnetic layer, and the second magnetically changeable ferromagnetic layer being disposed on the ferromagnetic reference layer, the method defining a writing event comprising: applying a pulse of a first magnetic field below a switching field along a first axis of the memory cell for a first duration; applying a pulse of a second magnetic field along a second axis orthogonal to the first magnetic field for a second duration which is shorter than the first duration, wherein the first magnetic field is turned-off after the second magnetic field is turned-off; determining whether a magnetization of one of the first and second magnetically changeable ferromagnetic layers has been through (n+½) precession cycles, where n is a number of precession cycles; and terminating the second magnetic field when the magnetization of one of the first and second magnetically changeable ferromagnetic layers has been through the (n+½) precession cycles.