磁性材料及元件應用技術──磁阻記憶體近期發展與挑戰

Magnetic Materials & Related Technological Applications--Recent Development and Challenge of Magneto-resistive Random Access Memory

隨半導體產業日新月異，電晶體微縮進展日新月異；即使逼近物理極限，各大研究團隊仍孜孜矻矻探究各種可能性。然而記憶體在微縮上卻難以望其項背，因此新興記憶體的需求也相應而生，磁阻式記憶體即為其中之一。磁阻式記憶體有著非揮發性的特質，且讀寫速度快，可覆寫次數高，使其成為極具潛力的候選者，然而其製程上卻有相當程度的挑戰，本文將從自旋轉移力（spin-transfer torque, STT）矩式記憶體出發，延伸到近期非常熱門的自旋軌道轉移矩（spin-orbit torque, SOT），探討相關技術的發展與瓶頸。

With the rapid development of the semiconductor industry, the progress of transistor miniaturization is made rapidly. Even though the physical limits are approaching, major research teams are still diligently exploring various possibilities. However, memory technology is not as good at miniaturization as it should be, so there is a demand for new memory, one of which is magneto-resistive random access memory (MRAM). MRAM has non-volatile properties, with fast read/write speed, and high overwriting frequency. These merits make it a promising candidate for next-generation memory technology. However, there are considerable challenges in MRAM in terms of the fabrication process. In this report, we explore the development and bottlenecks of this technology, first from the perspective of spin-transfer torque (STT) MRAM. We then extend to the spin-orbit torque (SOT) MRAM, which is a very popular research topic of the technology.