A method for manufacturing a magnetic memory element for use in a magnetic random access memory device to form a MgO spin current coupling layer with improved spin current coupling and reduced device area resistance (RA). The method involves depositing a magnetic free layer structure, and then depositing a MgO spin current coupling layer over the magnetic free layer. The magnetic spin current coupling layer is deposited in a sputter deposition chamber using radio frequency (RF) power. The sputter deposition of the spin current coupling layer can be performed using a MgO target without intervening oxidation steps to form a continuous layer of MgO that is not a multilayer structure of Mg and intermittent oxidation layers. Because the MgO spin transport layer deposited by this RF sputtering does not affect RA of the device, the thickness of the MgO spin transport layer can be adjusted to optimize spin transport performance.