Amorphous structure and bonding chemistry of aluminium antimonide(AlSb)) alloy for phase-change memory device

Abstract

With the help of first-principles molecular dynamics calculations, we obtained the atomic picture of amorphous AlSb(a-AlSb) for phase-change memory application. Generally, a-AlSb shows sp3 bonding network, which is the intrinsic characteristic for its good thermal stability. Significant wrong(homogenous) Al-Al bonds can also be observed from the pair correlation function. This hints the amorphous phase may consist of Al cluster and Sb-rich Al-Sb alloy. Recent experiment has observed the Sb-rich region of AlSb alloy can be switched to crystal, on the basis of which, combined with our calculations, we thus propose that on the one hand such a Sb-rich region in a-AlSb can retain the rapid crystallization like pure Sb solid and on the other hand some Al atoms play the important role of stabilizing Sb rich network with sp3 bonding. The present study offers a microscopic view to understand the phase change mechanism of AlSb alloy for information storage device.