Stability enhancement and resistance drift suppression of antimony thin films by hafnium oxide interlayers

Abstract

Antimony material was an important phase change ingredient, but its poor amorphous stability and high resistance drift limited its application in phase change memory. In this paper, hafnium oxide (HfO2) material with a wide gap was proposed to improve the properties of Sb. Sb/HfO2 composite films were prepared by magnetron sputtering. The amorphous thermal stability of Sb was significantly improved by HfO2 interlayers. Sb/HfO2 has high crystallization temperature (∼230 °C) and data retention temperature (∼155.3 °C for ten years). The addition of HfO2 interlayers decreased the resistance drift and suppressed the crystallization of the Sb materials, resulting in smaller the grain size. Stronger Sb–O bonds were formed at the interfaces. The distribution of surface electrostatic potential showed that Sb/HfO2 thin film had a more gentle surface morphology. In addition, the electrical performance of the device based on Sb/HfO2 thin film were tested and a lower power consumption was achieved. The results of our work show that Sb/HfO2 composite film is a promising high performance phase change storage material.

Keywords

• HfO2 interlayers
• Sb/HfO2
• Amorphous stability
• Resistance drift
• Electrical properties