Ovonic threshold switch (OTS) selectors are promising devices to suppress leakage current of emerging memories in a cross-point architecture. In this study, enhanced OTS selector performance by nitrogen doping on amorphous SiTe chalcogenide was analyzed by focusing on the sub-threshold region with different temperatures. The parameters of trap states including effective trap density, inter-trap distance, and activation energy are known to govern the subthreshold behaviors of amorphous chalcogenides. The parameters derived from a trap limited Poole-Frenkel based conduction model and Arrhenius plot closely correlate with the nitrogen doping effect on SiTe. Increased inter-trap distance, lowered trap density, and raised activation energy by N doping hamper electron hopping through trap states, thereby suppressing the leakage current.

Keywords: Ovonic threshold switch, Selector, Activation energy, Trap state, Nitrogen doping