Layer‐Dependent Effects of Interfacial Phase‐Change Memory for an Artificial Synapse

Two‐terminal‐based artificial synapses have attracted attention because their electronic properties can be applied to next‐generation computing. Herein, interfacial phase‐change memory (iPCM) devices based on sputter‐grown GeTe/Sb2Te3 are fabricated. The iPCM device exhibits excellent multilevel resistance switching via control of entropy by restricting the movement of Ge atoms. Based on this movement, the optimal pulse scheme and GeTe/Sb2Te3 layer are used to implement a tunable analog weight update of artificial synapses. The nonlinearity of 0.32 and 40 conductance states (GeTe/Sb2Te3)16 iPCM is achieved for long‐term potentiation and depression, respectively. This artificial synapse, which stably changes the gradual conductance value, has the potential for significant performance improvement of neuromorphic computing. GeTe/Sb2Te3 interfacial phase‐change memory (iPCM) is a superlattice structure using phase‐change materials. Ge atom movement, which limits its atomic arrangement, realizes low energy consumption and high operating speed. A method to implement artificial synaptic characteristics that can be applied to neuromorphic computing by utilizing the unique features of iPCM is presented.