Iridium-manganese-based tunnel magnetoresistance sensing element with tantalum-nitride buffer layer for increased thermal stability

A method of manufacturing a tunnel magnetoresistance (TMR) sensing element, the method comprising:

• fabricating a layer stack of the TMR sensing element, including:
• forming a tantalum-nitride (TaN) layer;
• forming a reference layer system comprising:
• a pinned layer having a fixed pinned magnetization;
• a reference layer having a fixed reference magnetization;
• a coupling interlayer arranged between the pinned layer and the reference layer;
• and
• a natural antiferromagnetic (NAF) layer comprising iridium-manganese (IrMn), wherein the NAF layer is formed in direct contact with the TaN layer, wherein the NAF layer is configured to hold the fixed pinned magnetization in a first magnetic orientation and hold the fixed reference magnetization in a second magnetic orientation, and wherein the direct contact of the NAF layer with the TaN layer increases a blocking temperature of the NAF layer;
• forming a magnetic free layer having a magnetically free magnetization, wherein the magnetically free magnetization is variable in a presence of an external magnetic field;
• and
• forming a tunnel barrier layer arranged between the reference layer system and the magnetic free layer.