High Performance All Nonmetal SiN_x Resistive Random Access Memory with Strong Process Dependence

Area of Science:

• Materials Science
• Electrical Engineering
• Semiconductor Physics

Background:

• Resistive random-access memory (RRAM) is a promising non-volatile memory technology.
• Silicon nitride (SiN_x) is explored as a dielectric layer in RRAM devices.
• Fabrication methods influence RRAM device performance.

Purpose of the Study:

• To investigate an all-nonmetal RRAM device with a N⁺-Si/SiN_x/P⁺-Si structure.
• To compare the performance of SiN_x films deposited by physical vapor deposition (PVD) and plasma-enhanced chemical vapor deposition (PECVD).
• To understand the impact of fabrication methods on RRAM characteristics.

Main Methods:

• Fabrication of SiN_x RRAM devices using PVD and PECVD methods.
• Characterization of device performance, including resistance window, endurance, and retention.
• Analysis of current-voltage characteristics to determine conduction mechanisms.
• Evaluation of device-to-device uniformity in set and reset voltages.

Main Results:

• PVD-fabricated SiN_x RRAM devices exhibited significantly better performance than PECVD devices.
• PVD devices showed a large resistance window (>10⁴), good endurance (10⁵ cycles), and retention time (10⁴ s at 85°C).
• PVD devices demonstrated tighter distribution of set and reset voltages, crucial for large-scale integration.

Conclusions:

• PVD is a superior method for fabricating high-performance SiN_x RRAM devices.
• The abundant defects in PVD-deposited SiN_x contribute to its enhanced electrical properties.
• PVD-based SiN_x RRAM is suitable for cross-point arrays and integration with CMOS technology for electronic neurons.