Heating Effect of Polycrystalline SiGe/Si Thin Films on Phase Transition of GeSbTe Films

Abstract

This work reports the detailed manufacturing process of polycrystalline SiGe/Si thin film layers and their heating effect on phase transition of GeSbTe chalcogenide films. The SiGe and Si films were grown successively by chemical vapor deposition, and different methods were applied to dope the SiGe films depending on their semiconducting nature because of phosphorus autodoping. Although the minimum dopant concentration for the n-type SiGe films was much higher than that for the p-type SiGe films, the lowest transition currents were measured almost same with both pand n-type SiGe films. The transition current decreased further with reducing contact area between the GeSbTe and SiGe films. These results indicate that the contact area scaling and the formation of SiGe/Si films with a dopant concentration smaller than a critical value are both required to induce the phase transition of GeSbTe at a submilliampere level of transition current. [doi:10.2320/matertrans.M2013084]