Magnetic random access memory (MRAM) with enhanced magnetic stiffness and method of making same

摘要

A spin transfer torque magnetic random access memory (STTMRAM) element and a method of manufacturing the same is disclosed having a free sub-layer structure with enhanced internal stiffness. A first free sub-layer is deposited, the first free sub-layer being made partially of boron (B), annealing is performed of the STTMRAM element at a first temperature after depositing the first free sub-layer to reduce the B content at an interface between the first free sub-layer and the barrier layer, the annealing causing a second free sub-layer to be formed on top of the first free sub-layer and being made partially of B, the amount of B of the second free sub-layer being greater than the amount of B in the first free sub-layer. Cooling down the STTMRAM element to a second temperature that is lower than the first temperature and depositing a third free sub-layer directly on top of the second free layer, with the third free sub-layer being made partially of boron (B), wherein the amount of B in the third sub-free layer is less than the amount of B in the second free sub-layer.

主权项

1. A method of manufacturing a spin transfer torque magnetic random access memory (STTMRAM) element that includes therein a junction layer, the method comprising:
a) depositing a bottom magnetic layer on top of a substrate; b) annealing the bare bottom magnetic layer at a first temperature prior to depositing the junction layer; c) cooling down the bare bottom magnetic layer to a second temperature that is lower than the first temperature; and d) depositing an interface magnetic layer directly on top of the bottom magnetic layer, the junction layer on top of the interface magnetic layer, and at least one top magnetic layer on top of the junction layer.