A HfO2/SiTe Based Dual-Layer Selector Device with Minor Threshold Voltage Variation

Volatile programmable metallization cell is a promising threshold switching selector with excellent characteristics and simple structures. However, the large variation of threshold voltage is a major problem for practical application. In this work, we propose a dual-layer structure to increase selectivity and improve the threshold voltage variation. Compared to single-layer devices, this dual-layer device exhibits higher selectivity (>107) and better threshold voltage uniformity with less than 5% fluctuation during 200 DC switching. The improvement is attributed to good control on the location of the filament formation and rupture after introducing a HfO2 layer. It is deduced that a major factor consists of the difference of Ag ions mobility between SiTe and HfO2 due to the grain boundary quantity.

Impact of radiation induced crystallization on programmable metallization cell electrical characteristics and reliability

Chalcogenide-based, programmable metallization cells (PMC) cells have been characterized after exposure to increasing levels of absorbed dose (i.e., ionizing radiation exposure).