Atomistic Studies of Germanium-Rich Selectors: Memory selectors made from alloys of germanium (Ge) and selenium (Se) are promising, but a better understanding of the physics underlying this alloy’s switching performance is needed, in order to optimize it. A team led by Imec performed advanced atomistic (i.e., atom-by-atom) computer simulations, coupled with physical experiments, to understand the underlying electrical and thermal dynamics and correlate them to carrier-transport properties. At the IEDM, they will report that a variety of factors including Ge conductive defects, electric field strength, and the number and position of trap states, affect the formation of filamentary paths for electrical current.
The image above is one of a series of atomic aGeSe models the researchers used in their work to simulate electronic structure/state localizations, electric field effects and thermal conductivity.
(Paper 4.1, “Atomistic Investigation of the Electronic Structure, Thermal Properties and Conduction Defects in Ge-rich GexSe1-x Materials for Selector Applications,” S. Clima et al, Imec/Univ. Leuven/Univ. Antwerp)