Technical Challenges in MRAM Fabrication

We have developed integration process for manufacturing spin-transfer torque (STT)-magnetic random access memory (MRAM). We have realized volume production of 64Mb chips and are ready to provide engineering samples with a capacity of up to 256Mb. In this paper, fundamental challenges in current CoFeB-and MgO-based STT-MRAM with perpendicular magnetic anisotropy (PMA) are highlighted in terms of materials and process aspects. The technical challenges in the key processes including chemical mechanical polishing (CMP), etching, and thin film deposition in MRAM fabrication are discussed in more details. Challenges and possible solutions related to device performance optimizations, scaling and reliability are also addressed.