SiNx RRAMs performance with different stoichiometries

TL;DR

This study investigates how varying the stoichiometry of SiNx thin films affects the performance of RRAM devices, demonstrating improved switching characteristics with non-stoichiometric compositions.

Contribution

It provides experimental insights into how adjusting SiNx stoichiometry influences resistive switching performance and device reliability.

Findings

Non-stoichiometric SiNx films show improved SET/RESET voltages.

Si-rich films have higher breakdown acceleration factors.

Stoichiometry tuning enables performance optimization of RRAMs.

Abstract

The microstructure of SiNx is strongly affected by its stoichiometry, x. The stoichiometry of SiNx thin films can be modified by adjusting the gas flow rates during LPCVD deposition. The deficiency or excess of Si atoms enhance the formation of defects such as nitrogen vacancies, silicon dangling bonds etc., and thus can enable performance tuning of the resulting MIS RRAM devices. DC electrical characterization, impedance spectroscopy and constant voltage stress measurements were carried out to investigate the properties of non-stoichiometric silicon nitride films as resistive switching material. The average SET time for each device was measured by applying voltage ramps. Improvement in the SET/RESET voltages and SET time is observed. Finally, the stoichiometric film exhibits the lowest breakdown acceleration factor, while the Si-rich film the highest.