Improved Switching Speed and Current Density of Conductive Bridge Threshold Switch Devices by Ag₂Se Layer

The large-scale 3-D crosspoint memory has received immense attention. However, the issue of crosstalk resulting from leakage current significantly impacts the memory cells. Conductive bridge threshold switching (CBTS) selector offers high selectivity and reduced leakage current, which can address this issue. Nevertheless, the limited switching speed and low current density ( <tex-math notation="LaTeX">JON)</tex-math> hinder its wider application. It is crucial to enhance the switching performance of CBTS. We propose a system that utilized Ag <tex-math notation="LaTeX">⁺</tex-math> as the conductive filaments (CFs) to improve <tex-math notation="LaTeX">JON</tex-math> and switching speed of the devices. This work demonstrates the excellent performance of a Pt/Ag <tex-math notation="LaTeX">₂</tex-math> Se/GeSe/Pt device. It exhibits ultrahigh selectivity (10 <tex-math notation="LaTeX">¹⁰</tex-math> ), high drive current <tex-math notation="LaTeX">Idrive</tex-math> (6 mA), and higher <tex-math notation="LaTeX">JON</tex-math> (15 mA/cm <tex-math notation="LaTeX">²</tex-math> ). Furthermore, the device exhibits improved switching speed <tex-math notation="LaTeX">tON</tex-math> / <tex-math notation="LaTeX">tOFF</tex-math> (70/50 ns) and an extremely steep switching slope (SS <tex-math notation="LaTeX">$<$</tex-math> 0.15 mV/dec). This selector shows threshold switching (TS) behavior by introducing Ag <tex-math notation="LaTeX">₂</tex-math> Se as the ion supply layer. It can inject Ag <tex-math notation="LaTeX">⁺</tex-math> ions into the GeSe layer to form CFs at high voltage and retract Ag <tex-math notation="LaTeX">⁺</tex-math> ions at low voltage. This CBTS selector achieves the significant enhancements in the switching speed and current density.