High density SOT-MRAM memory array based on a single transistor

Spin Orbit Torque Magnetic RAM (SOT-MRAM) approach represents a new way to overcome over Spin Transfer Torque (STT) memory limitations by separating the reading and the writing paths. It is particularly interesting for high speed applications that do not require very high density because of two transistors per bit cell. This paper presents a high density SOT-MRAM memory array based on a single transistor and a unidirectional diode. There are three advantages of this approach. The number of transistors for 32kb memory array is decreased by factor of 45% which leads to an improved cell density by 20% compared to conventional SOT bit cell. Moreover, it requires less control to read operation and finally high endurance, high speed and high density can be achieved. The key challenge going will be to adjust between sense margin and read energy.