Crystallization properties of materials along the pseudo-binary line between GeTe and Sb

Abstract

GeTe is a well-know prototypical phase change material, while pure Sb is described as a material with strong resonant bonding properties which are indicative of a fast switching phase change material. We have studied the crystallization times and crystallization temperatures of phase-change materials along the GeTe-Sb pseudobinary line with compositions Ge1SbxTe1. It was observed that alloys with x ≈ 1–2 show the highest crystallization temperature and resistance in the crystalline phase (indicative of low reset current) but also the slowest crystallization speed. As many phase change materials, Ge1SbxTe1 materials also suffer from conflicting requirements between speed, thermal stability of the amorphous phase, and low reset current. The Ge-Sb-Te phase-change material compositions must be carefully designed to optimize device performance for a specific application. Ge1Sb6Te1 material is a promising candidate for storage-class memory with fast speed and a crystallization temperature that is substantially higher than Ge2Sb2Te5 thus promises good data retention.