Hydrogen induced redox mechanism in amorphous carbon resistive random access memory

Area of Science:

• Materials Science
• Electrical Engineering
• Solid-State Physics

Background:

• Resistive random access memory (RRAM) offers promising non-volatile memory solutions.
• Understanding the switching mechanisms in novel RRAM materials is crucial for device optimization.
• Amorphous carbon layers present a unique material for RRAM applications.

Purpose of the Study:

• To investigate the bipolar resistive switching characteristics of RRAM devices utilizing an amorphous carbon layer.
• To elucidate the resistive switching mechanism in carbon RRAM.
• To propose a hydrogen redox model for explaining the high/low resistance states.

Main Methods:

• Fabrication of RRAM devices with an amorphous carbon layer.
• Application of forming voltage to induce carbonization and filament formation.
• Electrical characterization to analyze resistive switching behavior.
• Analysis using a proposed hydrogen redox model.

Main Results:

• Bipolar resistive switching was successfully demonstrated in the amorphous carbon layer RRAM.
• Carbonization under forming voltage created a conjugation double bond conductive filament.
• The low resistance state (LRS) is attributed to a conductive sp2 carbon filament via dehydrogenation.
• The high resistance state (HRS) is explained by an insulating sp3-type carbon filament formed through hydrogenation.

Conclusions:

• The hydrogen redox mechanism accurately explains the resistive switching behavior in carbon RRAM.
• Control over hydrogenation and dehydrogenation processes is key to managing the RRAM states.
• This research provides insights into developing advanced carbon-based RRAM devices.