Near-Linear Potentiation Mechanism of Gated Schottky Diode as a Synaptic Device

Abstract

The operation principle and near-linear potentiation mechanism of reconfigurable gated Schottky diodes (GSDs) are analyzed using calibrated device simulation. The reconfigurable GSD has two bottom gates and SiO2/Si3N4/SiO2 gate insulator stack. According to the polarity of the bottom gate bias, electrons, or holes are induced in the poly-Si active layer and the type of Schottky diodes is reconfigured. In the same manner, the reverse-biased current of GSD is modulated by applying bottom gate bias or storing charge in the Si3N4 charge storage layer. The reverse-biased current of GSD is exponentially proportional to the charge stored in the Si3N4 layer. By representing the amount of stored charge as a logarithmic relation to the number of potentiation pulses, the number of potentiation pulses, and the current of GSD has a power relation. It has been demonstrated that the GSD current exhibits near-linear potentiation characteristics when the exponent of the power relation is close to 1.