Reduced process degradation of spin torque magnetoresistive random access memory

A method of making a magnetic random access memory (MRAM) device, the method comprising:

• forming a magnetic tunnel junction (MTJ) on an electrode, the MTJ comprising a reference layer positioned in contact with the electrode, a free layer, and a tunnel barrier layer arranged between the reference layer and the free layer;
• and
• depositing a stoichiometric Si3N4 encapsulating layer directly on a top surface of the free layer and directly on sidewalls of the MTJ by physical sputtering of a target material onto the MTJ to form a silicon nitride film comprising stoichiometric Si3N4, the physical sputtering being performed with N2 and Ar gases, at a temperature in a range from about 20 to about 25° C., a power in a range from about 150 to 1000 Watts (W), and at a deposition rate in a range from about 8 Ångstrom/min (Å/min) to about 20 Å/min,
• wherein the silicon nitride film comprising stoichiometric Si3N4 forms a final film on the top surface of the free layer and the sidewalls of the MTJ.