Low-temperature characteristics of magnesium fluoride based bipolar RRAM devices

Abstract

This study investigates the temperature-independent switching characteristics of magnesium fluoride (MgF_x) 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_x and the trap-controlled space charge limited conduction (SCLC) mechanism in the bulk MgF_x 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_x active layer and Ti/MgF_x 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_x/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.