Hydrogen Doping on AlN-based Filamentary Selector for Switching Performance Improvement

Abstract

Large-scale cross-point memory arrays have become essential for high-density data storage in information-explosive computing era, but sneak-noise issues among adjacent cells have hindered reliable operation of the cross-point memory arrays. To resolve the issues, two-terminal threshold switching devices have been emerged as selectors that can be integrated vertically on the memory cells, thereby maintaining the cell density with reduction of leakage current. Among various types of threshold switching devices, electrochemical metallization (ECM) selectors, based on metallic filaments in a resistive media, show promising selecting performances such as low leakage current (< 1 pA). However, poor current driving ability and high switching variations should be addressed for stable and uniform array operation, respectively. I have discovered that hydrogen (H) doping in aluminum nitride (AlN) medium substantially improves the current driving ability and switching uniformity. The origin of such enhancement is suggested that reduction of dangling bond density in AlN by H dopants increases heterogeneous nucleation barrier of ECM in the medium, resulting in a regulation of excessive filament formation. The H doping can be one of the promising material strategies to address performance challenges of ECM selectors for large-scale cross-point memory arrays.