Designing Sb phase change materials by alloying with Ga2S3 towards high thermal stability and low resistance drift by bond reconfigurations

Abstract

The pure Sb phase-change thin films alloyed with Ga2S3 alloy have been prepared and the related properties have been investigated. Compared with pure Sb, Ga2S3-alloyed Sb films exhibit higher crystallization temperature (∼250 °C), larger ten-year data retention temperature (∼166 °C), and higher crystallization activation energy (4.10 eV). These thermal parameters indicate that the thermal stability of the Ga2S3-alloyed Sb thin films can be considerably enhanced due to the formation of high binding energy Sb-S and Sb-Ga bonds. Moreover, the enhanced thermal stability can also significantly lower resistance drift coefficient (0.0014). According to the analysis of the crystallization mechanism, the crystallization kinetic index (n) is determined to be 0.625, implying one-dimensional growth type in Ga2S3-alloyed Sb thin films. This can benefit to reduce the nucleation randomness and decrease resistance drift. The work demonstrates that Ga2S3-alloyed Sb materials have excellent potential for embedded memory applications.