The synaptic deviceis one of the most important components in the neuromorphic system, not only for performing intelligent tasks with lowpower consumption, but also to reduce a chip size. Thisis accomplished by integrating highly dense synapse arraysin deep neural network hardware [2]. Two-terminal basedemerging non-volatile memories such as resistive randomaccess memory (RRAM) [3], phase-change RAM (PRAM) [4],and magnetic RAM (MRAM) [5] have been actively studiedfor this purpose because of their small cell size. However,such memories have difficulty maintaining reliable operationand mass productivity. Also, the two-terminal memories needadditional circuitry components for selecting a target cell,when they are integrated in a system [6].