Study on the physical properties and structure of titanium antimony thin films for phase change memory application

Abstract

The phase change behaviors of titanium antimony thin films were examined as a function of Ti concentration by in situ electrical measurement. With the increment in titanium content, the crystallization temperature enhanced, while the electrical conductivity reduced. The sharp decline in carrier density is responsible for the drop of the electrical conductivity before and after crystallization. The amorphous and polycrystalline state was confirmed by means of selected area electron diffraction. The shift of Raman modes associated with Sb upon the phase transition was observed. The surface morphology and density fluctuation were obtained from atomic force microscopy and X-ray reflectivity. The interfacial adhesion strength between the titanium antimony thin films and silicon dioxide was implemented by Nano Indenter®. Based on Arrhenius plot and Johnson–Mehl–Avrami model, the crystallization kinetics including the crystallization activation energy, the crystallization mechanism and the Avrami coefficient were investigated as well. The obtained values of Avrami indexes illustrate one-dimensional growth-dominated mechanism of titanium antimony thin films.