ABSTRACT

This chapter focuses on the toggle magnetic random access memory (MRAM), developed by Motorola, Freescale Semiconductor, and Everspin Technologies. Toggle MRAM has been followed by spin transfer torque MRAM (STT-MRAM), which offers much higher storage density and greater scalability. The chapter discusses the potential and challenges of STT-MRAM. MRAM combines a set of properties not simultaneously available in any other memory technology: non-volatility, low-voltage operation, unlimited read and write endurance, high-speed read and write operation, excellent reliability, and radiation hardness. The chapter describes the fundamental properties governing single bit operation, the additional challenges of full array operation, the long-term reliability of MRAM, and the emerging MRAM applications. The dominating advantage of toggle MRAM is its greatly enhanced selectivity. In MRAM, reliability can be divided into well-known complementary metal-oxide-semiconductor reliability issues and new failure mechanisms related to the MRAM module itself.