Ge-Sb-Te thin films deposited by pulsed laser: An ellipsometry and Raman scattering spectroscopy study

被引：91
作者：
Nemec, P. [1 ]
Moreac, A. [2 ]
Nazabal, V. [3 ]
Pavlista, M. [4 ]
Prikryl, J. [1 ]
Frumar, M. [1 ]
机构：
[1] Univ Pardubice, Fac Chem Technol, Dept Gen & Inorgan Chem, Pardubice 53210, Czech Republic
[2] Univ Rennes 1, CNRS, UMR 6251, Inst Phys Rennes, F-35042 Rennes, France
[3] Univ Rennes 1, CNRS, UMR 6226, Equipe Verres & Ceram, F-35042 Rennes, France
[4] Univ Pardubice, Inst Appl Phys & Math, Pardubice 53210, Czech Republic
来源：
JOURNAL OF APPLIED PHYSICS | 2009年 / 106卷 / 10期
关键词：
PHASE-CHANGE MATERIALS; GE2SB2TE5; FILMS; OPTICAL-PROPERTIES; MEMORY; STORAGE; SEMICONDUCTORS; MECHANISM; DEVICES; GLASSES; ALLOYS;
D O I：
10.1063/1.3259435
中图分类号：
O59 [应用物理学];
学科分类号：
摘要：
Pulsed laser (532 nm) deposited Ge2Sb2Te5 thin films were investigated by means of spectroscopic ellipsometry and Raman scattering spectroscopy. Tauc-Lorentz and Cody-Lorentz models were employed for the evaluation of optical functions of thin films in as-deposited (amorphous) and crystalline (cubic) phases. The models' parameters (Lorentz oscillator amplitude, resonance energy, oscillator width, optical band gap, and Urbach energy) calculated for amorphous and crystalline states are discussed. The vibrational modes observed in Raman spectra of amorphous layers are attributed to GeTe4-nGen (n=1, 2, eventually 0) tetrahedra connected by corners (partly by edges) and SbTe3 units. The Raman spectra of crystalline thin films suggest that the local bonding arrangement around Ge atoms changes; GeTe component is thus mainly responsible for the phase transition in Ge2Sb2Te5 alloys. (C) 2009 American Institute of Physics. [doi:10.1063/1.3259435]
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页数：7
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