Epitaxial Ge2Sb2Te5 Films on Si(111) prepared by Pulsed Laser Deposition

Publication date: Available online 12 October 2016
Source:Thin Solid Films
Author(s): I. Hilmi, E. Thelander, P. Schumacher, J.W. Gerlach, B. Rauschenbach
Epitaxial Ge2Sb2Te5 (GST) thin films were successfully grown on Si(111) using pulsed laser deposition (PLD) at various substrate temperatures and pulsed laser beam frequencies. The films were characterized by x-ray diffraction regarding crystallinity, phase composition and texture. The films possess a hexagonal structure with a GST(0001) out-of-plane orientation. With increasing substrate temperature, the deposition rate decreases due to severe surface desorption during deposition as determined by x-ray reflectivity measurements. The deposition window for epitaxial growth ranges from 110° to 300°C. The topography of the films shows triangularly shaped crystallites and the RMS roughness is typically around 0.6nm for the films deposited between 200°C and 250°C. Single crystalline GST films could be synthesized with deposition rates of as high as 42nm/min by varying the laser repetition frequency.