CMOS Compatible Process Integration of SOT-MRAM with Heavy-Metal Bi-Layer Bottom Electrode and 10ns Field-Free SOT Switching with STT Assist
Noriyuki Sato, Gary Allen, William P. Benson, Benjamin Buford, Atreyee Chakraborty, Michael Christenson, Tanay A. Gosavi, P. Heil, Nafees Kabir, B. Krist, Kevin O’Brien, Kaan Oguz, Rohan Patil, J. P. Pellegren, Angeline Klemm Smith, Emily Walker, P. Hentges, M. Metz, M. Seth, B. A. Turkot, Christopher J. Wiegand, Hui Jae Yoo, Ian A. Young
Abstract
This paper demonstrates a CMOS compatible process integration of spin-orbit torque (SOT) device with a unique bi-layer SOT bottom electrode. An effective spin-Hall angle of 0.27, a median tunneling magneto-resistance ratio of 127% at electrical CD of 57 nm, and a 96% resistance-based MTJ yield on 300 mm scale were achieved. We experimentally validated the two-pulse field-free SOT switching scheme with spin-transfer torque assist at 10 ns. Unlike conventional field-free SOT switching schemes, the demonstrated scheme adds no complexity to process integration.