Ion Beam Etching Technology for High-Density Spin Transfer Torque Magnetic Random Access Memory

Abstract

A spin transfer torque magnetoresistive random access memory (STT-MRAM) is the most promising candidate for a non-volatile random access memory, because of its scalability, high-speed operation, and unlimited read/write endurance. An ion beam etching (IBE) is one of the promising etching methods for a magnetic tunnel junction (MTJ) of the STT-MRAM, because it has no after-corrosion and oxidation problems. In this work, we developed the multiple-step wafer-tilted IBE using computer calculation. Using optimized multiple-step IBE conditions, we fabricated MTJs without barrier-short defects.