Analysis and Control of RRAM Overshoot Current

Area of Science:

• Materials Science
• Electrical Engineering
• Semiconductor Device Physics

Background:

• Resistive Random-Access Memory (RRAM) exhibits significant variability, often addressed by current compliance elements during forming.
• Current overshoot during RRAM forming, regardless of compliance (1R-1R, 1T-1R), is a known phenomenon.
• The peak overshoot current has been conventionally linked to filament characteristics and parasitic capacitance.

Purpose of the Study:

• To investigate the relationship between parasitic capacitance and current overshoot during RRAM forming.
• To clarify the role of overshoot current characteristics in the success of ultra-short pulse forming.
• To challenge the conventional understanding of peak overshoot current as a predictive metric.

Main Methods:

• Detailed circuit analysis of 1R-1R and 1T-1R structures.
• Experimental measurements on RRAM test structures.
• Comparison of ultra-short pulse forming with conventional methods.

Main Results:

• The peak overshoot current is independent of parasitic capacitance.
• The duration of the current overshoot is strongly dependent on parasitic capacitance.
• Ultra-short pulse forming achieves control because overshoot duration is less than pulse duration.

Conclusions:

• Parasitic capacitance does not influence the peak overshoot current in RRAM forming.
• Overshoot duration is the key parameter for controlling RRAM forming, particularly with ultra-short pulses.
• The success of compliance-free ultra-short pulse forming is explained by controlling overshoot duration.