Improved Device Distribution in High-Performance SiN_x Resistive Random Access Memory via Arsenic Ion Implantation

Area of Science:

• Materials Science
• Electrical Engineering
• Semiconductor Devices

Background:

• Device-to-device variation is a critical challenge in resistive random access memory (RRAM) array circuits.
• Silicon nitride (SiNx) RRAM devices suffer from inconsistent set and reset voltage distributions, limiting their practical application.
• Existing RRAM technologies require optimization to achieve high stability and endurance for advanced memory applications.

Purpose of the Study:

• To investigate the impact of arsenic ion (As+) implantation on the performance of SiNx RRAM devices.
• To improve the device-to-device and cycle-to-cycle uniformity of set and reset voltages in SiNx RRAM.
• To analyze the underlying mechanism responsible for the enhanced performance of As+-implanted SiNx RRAM.

Main Methods:

• Arsenic ion (As+) implantation was performed on SiNx RRAM devices.
• Device-to-device and cycle-to-cycle distributions of set and reset voltages were measured.
• High-temperature retention and pulsed endurance tests were conducted to evaluate device stability.
• Current-voltage characteristics were analyzed, and a microscopic model based on simulated defect distribution was established.

Main Results:

• As+ implantation significantly improved the device-to-device distributions of set and reset voltages in SiNx RRAM.
• The As+-implanted SiNx RRAM exhibited much tighter cycle-to-cycle distributions compared to non-implanted devices.
• The implanted devices demonstrated excellent stability with a large 1.73 × 10^3 resistance window at 85 °C for 10^4 s and a 10^3 resistance window after 10^5 cycles.
• Space-charge-limited conduction was identified as the mechanism for both high and low resistance states.
• The formation and rupture of defect-conductive paths, facilitated by As+ implantation-induced defects, were proposed as the switching mechanism.

Conclusions:

• Arsenic ion implantation is an effective method for enhancing the performance and reliability of SiNx RRAM devices.
• The improved performance is attributed to the increased defect density created by As+ implantation, leading to lower forming and operation power.
• The study provides a microscopic understanding of the resistance switching behavior in SiNx RRAM, paving the way for optimized RRAM fabrication.