Threshold resistance switching in silicon-rich SiOx thin films**Project supported by the Open Project Program of Surface Physics Laboratory (National Key Laboratory) of Fudan University, China (Grant No. KF2015_02), the Open Project Program of National Laboratory for Infrared Physics, Chinese Academy of Sciences (Grant No. M201503), Zhejiang Provincial Science and Technology Key Innovation Team, China (Grant No. 2011R50012), and Zhejiang Provincial

Abstract

Si-rich SiOx and amorphous Si clusters embedded in SiOx films were prepared by the radio-frequency magnetron cosputtering method and high-temperature annealing treatment. The threshold resistance switching behavior was achieved from the memory mode by continuous bias sweeping in all films, which was caused by the formation of clusters due to the local overheating under a large electric field. Besides, the I–V characteristics of the threshold switching showed a dependence on the annealing temperature and the SiOx thickness. In particular, formation and rupture of conduction paths is considered to be the switching mechanism for the 39 nm-SiOx film, while for the 78 nm-SiOx film, adjusting of the Schottky barrier height between insulator and semiconductor is more reasonable. This study demonstrates the importance of investigation of both switching modes in resistance random access memory.