Patent ID: 8623452
Filing Date: 2014-01-07
Classification: G11C,H01L,Y10T

Abstract:
1. A method of manufacturing a spin transfer torque magnetic random access memory (STTMRAM) element comprising: first depositing a first free sub-layer on top of a barrier layer to form a magnetic tunnel junction (MTJ), the first free sub-layer being made partially of boron (B) and having a first within-film magnetic exchange; after the first depositing step, annealing the STTMRAM element at a first temperature after depositing the first free sub-layer, the annealing causing a second free sub-layer to be formed on top of the first free sub-layer after the annealing step, cooling down the STTMRAM element to a second temperature that is lower than the first temperature; and after the cooling down step, second depositing a third free sub-layer directly on top the second free sub-layer, the first, second, and third free sub-layers forming a free layer, wherein the third free sub-layer having a second within-film magnetic exchange, the second within-film magnetic exchange being different than the first within-film magnetic exchange, the amount of B in the third sub-free layer being less than the amount of B in the second free layer.