In silico screening for As/Se-free ovonic threshold switching materials

Abstract

Restricted use of hazardous environmental chemicals is one important challenge that the semiconductor industry needs to face to improve its sustainability. Ovonic threshold switching (OTS) ternary compound materials used in memory selector devices contain As and Se. Engineering these elements out of these materials requires significant research effort. To facilitate this process, we performed systematic material screening for As/Se-free ternary materials, based on ab-initio simulations. To limit the large amount of possible chemical compositions to fewer promising candidates, we used physics-based material parameter filters like material stability, electronic properties, or change in polarizability. The OTS gauge concept is introduced as a computed parameter to estimate the probability of a material to show an OTS behavior. As a result, we identified 35 As/Se-free ternary alloy compositions for stand-alone OTS memory applications, as well as 12 compositions for RRAM selector applications. This work aims seeding the development of As/Se-free OTS materials.