Ga-Sn-O thin film, mist-CVD method, and analog memristor: promising proposals for neuromorphic systems

Abstract

Promising proposals of a material, deposition process, and storage device have been demonstrated for neuromorphic systems. The material is Ga-Sn-O (GTO), amorphous metal-oxide semiconductor, and does not contain rare metals such as In. The deposition process is a mist chemical-vapor-deposition (CVD) method, atmospheric pressure process. Therefore, the material and fabrication costs can be simultaneously saved, and three-dimensional stacked structures will be possible. The storage device is an analog memristor, a kind of memristors, but has continuous conductance, and analog computing will be possible owing to continuous weights of synapse elements in neural networks. These structures and computing are the same as those in living brains. We have succeeded in attaining an analog memristive characteristic by optimizing the Ga:Sn composition rate, namely, completing an analog memristor. The analog memristor of the GTO thin film by the mist CVD method can be expected to be a key component for neuromorphic systems.