Programming Characteristics of Electrochemical Random Access Memory (ECRAM)—Part I: Experimental Study

Electrochemical random access memory (ECRAM) based on transition metal oxides is a promising candidate as a next-generation synaptic device for in-memory computing (IMC), due to its highly linear weight update characteristic and compatibility with the CMOS process. Understanding the conductance modulation mechanisms is essential to better improve device performance, reliability, and scalability. This work addresses the programming characteristics of ECRAM devices with WO <tex-math notation="LaTeX">ₓ</tex-math> channel and Ta <tex-math notation="LaTeX">₂</tex-math> O <tex-math notation="LaTeX">₅</tex-math> electrolyte. Large conductance modulation is achieved under quasistatic transcharacteristic measurements and interpreted with a nonlinear ionic drift-diffusion mechanism for oxygen vacancy migration. The linear conductance update is characterized as a function of pulse voltage amplitude and time duration, and the limits of the small signal approximation are discussed and experimentally assessed.