Effect of Ge Content on the Formation of Ge Nanoclusters in Magnetron-Sputtered GeZrOx-Based Structures.
Ge-rich ZrO2films, fabricated by confocal RF magnetron sputtering of pure Ge and ZrO2targets in Ar plasma, were studied by multi-angle laser ellipsometry, Raman scattering, Auger electron spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction for varied deposition conditions and annealing treatments. It was found that as-deposited films are homogeneous for all Ge contents, thermal treatment stimulated a phase separation and a formation of crystalline Ge and ZrO2. The "start point" of this process is in the range of 640-700 °C depending on the Ge content. The higher the Ge content, the lower is the temperature necessary for phase separation, nucleation of Ge nanoclusters, and crystallization. Along with this, the crystallization temperature of the tetragonal ZrO2exceeds that of the Ge phase, which results in the formation of Ge crystallites in an amorphous ZrO2matrix. The mechanism of phase separation is discussed in detail.
V. Lashkaryov Institute of Semiconductor Physics of NAS of Ukraine, 45 Pr.Nauky, 03028, Kyiv, Ukraine. khomen@ukr.net.
L
L
Khomenkova
Institute of Applied Physics, TU Bergakademie Freiberg, D-09596, Freiberg, Germany.
D
D
Lehninger
V. Lashkaryov Institute of Semiconductor Physics of NAS of Ukraine, 45 Pr.Nauky, 03028, Kyiv, Ukraine.
O
O
Kondratenko
V. Lashkaryov Institute of Semiconductor Physics of NAS of Ukraine, 45 Pr.Nauky, 03028, Kyiv, Ukraine.
S
S
Ponomaryov
V. Lashkaryov Institute of Semiconductor Physics of NAS of Ukraine, 45 Pr.Nauky, 03028, Kyiv, Ukraine.
O
O
Gudymenko
V. Lashkaryov Institute of Semiconductor Physics of NAS of Ukraine, 45 Pr.Nauky, 03028, Kyiv, Ukraine.
Z
Z
Tsybrii
V. Lashkaryov Institute of Semiconductor Physics of NAS of Ukraine, 45 Pr.Nauky, 03028, Kyiv, Ukraine.
V
V
Yukhymchuk
V. Lashkaryov Institute of Semiconductor Physics of NAS of Ukraine, 45 Pr.Nauky, 03028, Kyiv, Ukraine.
V
V
Kladko
Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, D-01314, Dresden, Germany.
J
J
von Borany
Institute of Applied Physics, TU Bergakademie Freiberg, D-09596, Freiberg, Germany.
J
J
Heitmann
Auger electron spectroscopy; Ellipsometry; Fourier Transform infrared spectroscopy; Germanium; Magnetron sputtering; Nanoclusters; Phase separation; Raman scattering; Thin films; X-ray diffraction; Zirconium oxide