TaOx-/TiO2-Based Synaptic Devices

The development of a high-density, low-power, and reliable synaptic device is essential in the implementation of highly anticipated hardware neural networks. Hence, numerous studies have investigated suitable two-terminal synaptic devices that precisely mimic biological synaptic features. In this chapter, we reviewed the development of a Ta/TaO_x/TiO₂/Ti resistive switching memory (RRAM) as a promising synaptic device technology for future neuromorphic computing systems. First, we reviewed the basic memory characteristics of the device and introduced a switching mechanism through electrical measurements and physical simulations. Second, we found that the device was particularly suitable for analog synapses, where several synaptic characteristics were demonstrated; moreover, we built a compact model to simulate these characteristics. Finally, a three-dimensional (3D) synaptic network was realized. In this chapter, we discussed the nonlinear weight update of the device and proposed an identical pulse training scheme for its improvement.