High-K and magnetic material for Voltage controlled (VCMA) MRAM applications

With the need for more power efficient and better performing memory devices, DRAM and SRAM are reaching their limit for further improvements. One promising replacement is magnetic random-access memory, or MRAM, where the bit state is stored in nano-scale magnetic layers. Due to its magnetic nature, MRAM is non-volatile thus requiring no external power to maintain the stored information. MRAM products are already commercially available though more improvements are needed to further reduce power consumption. One way in achieving that, is by using materials that have a voltage-controlled magnetic anisotropy (VCMA). By setting a voltage across these materials the energy barrier needed to flip the bit state is lowered, resulting in less power consumption. The VCMA effect nowadays is still found to be too weak for real applications and understanding of this effect limited. What is understood is that VCMA is a surface dependent phenomenon and occurs at the interface of a ferromagnet and an oxide. The PhD starts by studying the literature to understand the state-of-the-art of VCMA technology. From this literature study promising materials will be selected and their properties are then characterized. Then the possibility of using these materials in magnetic tunnel junctions is examined. When this turns out to be successful these new magnetic tunnel junctions can be integrated in the sub 1X nm technology node. All this work will be done at imec, Leuven.