Select Devices for Nanoscale Memory

Udayan Ganguly
Indian Institute of Technology, Bombay / India

Selection devices are required to enable large arrays for emerging memories for RRAM, STTRAM in a cross-point architecture. The goal is Flash, DRAM replacement in stand-alone as well as embedded applications. High on current density and non-linearity, 4F2 size, 3D stackability are the conventional requirements. Ambipolar selectors for bipolar operation is attractive for energy efficient bipolar RRAM and fast STTRAM. New devices such as MIEC selector by IBM, MIT based VO2 selector, tunneling based MIM selector, Ovonic Threshold Switch (OTS) by Intel etc. and punch-through diode based NPN selectors have been proposed. Challenges like dynamic power, variability and compatibility with myriad RRAM technologies with say different operating voltages & currents are new challenges that have been identified. Based on these holistic set of requirements, the various selector devices is evaluated to identify further technical challenges and opportunities.