Embodiments of the disclosure provide methods and apparatus for fabricating magnetic tunnel junction (MTJ) structures on a substrate in for spin-transfer-torque magnetoresistive random access memory (STT-MRAM) applications. In one example, a film stack utilized to form a magnetic tunnel junction structure on a substrate includes a pinned layer disposed on a substrate, wherein the pinned layer comprises multiple layers including at least one or more of a Co containing layer, Pt containing layer, Ta containing layer, an Ru containing layer, an optional structure decoupling layer disposed on the pinned magnetic layer, a magnetic reference layer disposed on the optional structure decoupling layer, a tunneling barrier layer disposed on the magnetic reference layer, a magnetic storage layer disposed on the tunneling barrier layer, and a capping layer disposed on the magnetic storage layer.