Using External Magnetic Field for Increasing STT-RAM Read/Write Reliability

In recent years, we have been witnessing the rise of spin-transfer torque random access memory (STT-RAM) technology. There are a couple of reasons which explain why STT-RAM has attracted a great deal of attention. Although conventional memory technologies like SRAM, DRAM and Flash memories are commonly used in the modern computer industry, they have major shortcomings, such as high leakage current, high power consumption and volatility. Although these drawbacks could have been overlooked in the past, they have become major concerns. Its characteristics, including low-power consumption, fast read-write access time and non-volatility make STT-RAM a promising candidate to solve the problems of other memory technologies. However, like all other memory technologies, STT-RAM has some problems such as cell-to-cell process variations and intrinsic thermal fluctuations which are waiting to be solved. In order to solve these variations and improve read/write reliability, we propose the utilization of an external magnetic field. When an external magnetic field is applied to a magnetic tunnel junction (MTJ) during a read operation, a self-reference resistive signal will be generated. This self-reference resistance is a very important technique for improving read reliability. In addition, external magnetic field can also be used for improving MTJ switching time