Bidirectional Two-Terminal Switching Device for Non-Volatile Random Access Memory

Abstract

A two-terminal N+/P/N+ Si junction device that can replace the conventional selective transistor was studied as a bilateral switching device for spin transfer torque magnetic random access memory (STT-MRAM), by three-dimensional device simulation. An N+/P/N+ junction structure with 30 x 30nm(2) area provides sufficient bidirectional current flow to write data by a drain-induced barrier lowering (DIBL) under a reverse bias at the N+/P (or P/N+) junction, and high current on/off ratio of 10(6), which is acceptable for STT-MRAM. In this work, critical parameters such as P-length, P doping, and N+ doping are investigated to elucidate the optimal parameter condition in view of write current and current on/off ratio.