The Backend Selector: from material development to device performance
Published : 15 July 2019
The maturity of non-volatile resistive memory technologies NVRM (such as phase-change memory PCM) for both Storage Class Memory (SCM) and embedded applications has demonstrated in recent years the need for the development of a reliable backend selector device to replace transistor selection. This technology allows the stacking of multiple levels of memory in 3D, in a so-called “Crossbar” architecture, increasing the storage density while taking advantage of the extraordinary performances of NVRM devices. LETI is today at the state of the art regarding the development of materials for integration into backend selector devices, especially for Ovonic Threshold Switching selectors (OTS). In the framework of this PhD new materials will be explored to meet the required specifications in terms of endurance, temperature stability, threshold voltage and scalability capability becoming more and more stringent. For this, the understanding of the physics and of the phenomena related to the functionality of these devices becomes fundamental. In addition, innovative memory+selector co-integration architectures will be investigated to finally achieve the integration of these solutions in an advanced Crossbar demonstrator.
The candidate should preferably have a very good level of knowledge in semiconductor physics and materials science. The candidate will be in contact with experts from different fields because of the multidisciplinary nature of the work (materials, integration, electrical and physicochemical characterization, and modeling). In addition, good team spirit and a good English language proficiency is required.