The Electrical and Structural Properties of Nitrogen Ge1Sb2Te4 Thin Film

The present work describes the process of obtaining thin films of Ge1Sb2Te4 by means of the short-pulse High Power Impulse Magnetron Sputtering (HiPIMS) technique. The Ge1Sb2Te4 (GST-124) and nitrogen Ge1Sb2Te4 (nitrogen GST-124) films were obtained in HiPIMS plasma ignited in Ar/GST-124 and Ar/N-2/GST-124, respectively. In particular, the possibility of tailoring the electrical properties of films for applications in the phase change memory (PCM) cells was investigated. The I-V measurements performed in a voltage sweeping mode on GST-124 and nitrogen GST-124 show that the threshold switching voltage varies as a function of nitrogen level in HiPIMS plasma. Amorphous-to-crystalline trigonal phase transition of the films was induced by thermal annealing, and structural changes were identified using X-ray diffraction and Raman scattering spectroscopy. The most intense bands appeared for the annealed layers in the range of 138-165 cm(-1), for GST-124, and 138-150 cm(-1) for nitrogen GST-124, respectively.