Integrated chalcogenide switch device by reactive nitrogen and plasma treatment for stackable scalable 3D nanoscale memory
Journal
Nature Communications
Date
2013.10.16
Abstract
The two basic components of random access memory devices are the select switch and storage node. It is required to improve the performance of both of these elements in order to achieve extreme high density memory beyond 1Terabit. Furthermore both components will be required to be compatible with technologies such as three-dimensional (3D) cell stacking, multi-level cell, endurance and scaling down below 10 nm node1,2. Resistive random access memory (RRAM) has been considered to be one of the most promising candidates to overcome scaling limits of the conventional memory due to its scalability, data retention (non-volatility), fast switching speed, and low power consumption3-14. In a high density memory system such as DRAM, a select device is required to suppress sneak current paths3,8,9. Current select devices have been Si-based transistors to obtain sufficient on-current density and reliability. However, the three terminal Si transistors are not suitable for 3D cross-bar stacked structure due to their high processing temperature and difficulty in both scaling and stacking8,9. Previously stackable select devices such as the oxide p-n junction diode8 and the Schottky diode15 have been proposed for a unipolar resistive switching RRAM device8,15, a bidirectional select device (or two-way switch) still needs to be developed for the bipolar resistive switching RRAM devices16. Recently various bidirectional select devices, for instance the varistor-type switch17 and MIEC device18 have been proposed for bipolar resistive memory applications. We report on a fully stackable switching device which solves several problems including current density for nanoscale devices, high temperature stability, cycling endurance, and cycle distribution.