Electroforming-Free Bipolar Resistive Switching Memory Based on Magnesium Fluoride

Electroforming-free resistive switching random access memory (RRAM) devices employing magnesium fluoride (MgF_x) as the resistive switching layer are reported. The electroforming-free MgF_x based RRAM devices exhibit bipolar SET/RESET operational characteristics with an on/off ratio higher than 10² and good data retention of >10⁴ s. The resistive switching mechanism in the Ti/MgF_x/Pt devices combines two processes as well as trap-controlled space charge limited conduction (SCLC), which is governed by pre-existing defects of fluoride vacancies in the bulk MgF_x layer. In addition, filamentary switching mode at the interface between the MgF_x and Ti layers is assisted by O-H group-related defects on the surface of the active layer.