Switching, Raman and morphological studies on Si20Te74Sn6 chalcogenide glass

Abstract

Chalcogenide materials are getting lot of research attention due to their ability to switchfrom an amorphous to a crystalline phase with lower threshold voltage which is a primary requirement for fabricating phase-change memory. Here we have prepared the Si20Te74Sn6 bulk sample using melt quenching technique. It has been observed that the sample exhibits a memory switching phenomenon with the addition of Sn dopant on Si-Te base glasses. Memory switching is mainly observed due to Te rich host matrix and the metallicity of Sn dopant. The sample exhibits a linear variation of threshold voltage with an increase in thickness, which is compatible with memory switching behaviour. Raman studies on as-quenched Si20Te74Sn6 glass are carried out to study the structural behaviour of the network. The observed Raman peaks are attributed to crystalline tellurium and the vibrational modes of Sn/Si lattice. Morphological studies on switched and un-switched samples using SEM reveal a structural alteration in the switched region, which can also be related to the creation of conducting channel between two electrodes during memory switching.