Crystallization and electrical conversion behavior of Ge1Sb9/HfO2 superlattice-like phase change films

Abstract

This paper focused the effect of the recombination of HfO2 on the phase change behavior and crystalline properties of Ge1Sb9/HfO2 superlattice-like phase change films. Compared with pure Ge1Sb9, the Ge1Sb9/HfO2 superlattice-like film has higher crystallization temperature, better data retention ability and larger activation energy, indicating excellent thermal stability. With the increase of HfO2 thickness ratio, the band gap becomes wider. Atomic force microscopy and X-ray diffraction tests illustrate that HfO2 composite layers can inhibit the growth of grain, reduce the grain size and have a smoother surface. X-ray reflectivity tests show that Ge1Sb9/HfO2 film has a small volume fluctuation during the crystallization process. Raman spectroscopy is used to observe the molecular vibration. Phase change memory devices based on Ge1Sb9/HfO2 thin film are fabricated to evaluate its electrical performance. The results reveal that HfO2 composite layers play a significant role in improving thermal stability, refining grain size and reducing power consumption on Ge1Sb9 phase change film.

Keywords

• Phase change memory
• Superlattice-like films
• Ge1Sb9/HfO2
• Thermal stability
• Low power consumption