Direct observation of phase transition of GeSbTe thin films by Atomic Force Microscope

摘要: Abstract GeSbTe (GST) thin films were deposited on quartz substrates using electron beam evaporation system and then annealed in nitrogen atmosphere at different temperatures, ranging from 20 °C to 300 °C. X-ray diffraction (XRD) Atomic Force microscope (AFM) measurements used characterize the as-deposited post-annealed films. Annealing treatment was found induce changes microstructure, surface roughness grain size, indicating that with increase of annealing temperature, amorphous GST first changed face-centered-cubic (fcc) phase stable hexagonal (hex) phase. Meanwhile, conductive-AFM (C-AFM) produce crystallized dots I–V spectroscopy results show can switch state crystalline threshold voltage. After switching, curve exhibits ohmic characteristic, which is usually observed By applying repeated spectroscopies films, nuclei observed. As times increases, area written center mark begin ablate. The AFM images shape marks an ablated a raised ring surrounding it.