Effect of Transistor Transfer Characteristics on the Programming Process in 1T1R Configuration

The one-transistor-one-resistor (1T1R) structure has been widely used in the context of novel neuromorphic applications. It can effectively control the state variability in redox-based resistive random access memory (ReRAM) and suppress the leakage current in ReRAM arrays. Since the transistor size has a direct impact on the electrical behavior, matching the characteristics of the two components in the 1T1R structure is a crucial step at the beginning of the device design. In this article, we focus on valence change mechanism (VCM)-type ReRAM devices and investigate the effect of the transistor transfer characteristics on the programming characteristics of 1T1R structures. By comparing the electrical behavior of three types of 1T1R structures with different transistor sizes during a gradual SET switching algorithm, we analyze how the applied voltage is distributed between the ReRAM cell and the transistor. Furthermore, the relationship among the transistor size, the operating region, and the bias conditions is explored based on the JART VCM v1b compact model. Finally, we discuss the effects of these factors on the programming characteristics of 1T1R structures and provide design suggestions regarding transistor size and bias conditions.