R&D: Improvement in Thermal Stability and Crystallization Mechanism of Sm Doped Ge2Sb2Te5 Thin Films for PCM Applications

Journal of Alloys and Compounds has published an article written by Sanjay, Kumar, and Vineet, Sharma, Department of Physics and Materials Science, Jaypee University of Information Technology, Waknaghat, Solan, H.P. 173234, India.

Abstract: “The thin films of (Ge₂Sb₂Te₅)_100−xSm_x (x=0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2) (Sm-GST) phase change material have been investigated employing X-ray photoelectron spectroscopy (XPS) to examine the nature of chemical bonding in as-deposited thin films of Sm-GST. The composition of as-deposited thin films of Sm-GST has been also analyzed from the peak area ratios of XPS core-level spectra and the morphology of the thin film has been studied using field emission scanning electron microscopy (FESEM). The powder samples obtained from the as-deposited thin films have been utilized for the non-isothermal differential scanning calorimetry (DSC) measurements at the constant heating rate of 10 K/min. The values of glass transition temperature (T_g), onset crystallization (T_c), peak crystallization temperature (T_p) and melting temperature (T_m) obtained from DSC curves of Sm-GST thin films have been used for the evaluation of thermal stability parameters. The activation energy for crystallization (E_c) and avrami exponent (n) for fcc and hexagonal phase of Sm-GST thin films have been evaluated using Henderson’s method and Matusita’s method. The impact of Sm doping on the thermal stability, glass-forming ability and crystallization activation energy of as-deposited thin films have been examined and its possible influence on the memory device performance has been correlated.“