Low-temperature characteristics of magnesium fluoride based bipolar RRAM devices

This study investigates the temperature-independent switching characteristics of magnesium fluoride (MgF) based bipolar resistive memory devices at temperatures ranging from 300 K down to 77 K. Filament type resistive switching at the interface of Ti/MgF and the trap-controlled space charge limited conduction (SCLC) mechanism in the bulk MgF layer are confirmed. The experimental results indicate that the operating environment and temperature critically control the resistive switching performance by varying the non-stoichiometry of the amorphous MgF active layer and Ti/MgF interface region. The gaseous atmosphere (open air or vacuum) affects device performances such as the electroforming process, on-state current, off-state current, on/off ratio, SET/RESET voltage and endurance of resistive-switching memory devices. After electroforming, the device performance is independent of temperature variation. The Ti/MgF/Pt memory devices show promising data retention for >10⁴ s in a vacuum at room temperature and 77 K with the DC endurance property for more than 150 cycles at 77 K. The devices have great potential for future temperature-independent electronic applications.