Characterizing the effects of etch-induced material modification on the crystallization properties of nitrogen doped Ge₂Sb₂Te ₅

Abstract

The chemical and structural effects of processing on the crystallization of nitrogen doped Ge2Sb2Te5 is examined via x-ray photoelectron spectroscopy (XPS), x-ray absorption spectroscopy (XAS), time resolved laser reflectivity, and time resolved x-ray diffraction (XRD). Time resolved laser reflectivity and XRD show that exposure to various etch and ash chemistries significantly reduces the crystallization speed while the transition temperature from the rocksalt to the hexagonal phase is increased. XPS and XAS attribute this to the selective removal and oxidization of N, Ge, Sb, and Te, thus altering the local bonding environment to the detriment of device performance. © 2011 American Institute of Physics.