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Home > Issues > Volume 12 (2007) > No.4(pp.133-161)

Synthesis and Quality of Cr-doped AIN Thin Films Grown by RF Sputtering

Journal of Magnetics, Volume 12, Number 4, 31 Dec 2007, Pages 149-151
Pham Hong Quang(Faculty of Physics, Hanoi University of Science), Tran Quang Hung(Department of Materials Science and Engineering, Chungnam National University), Ngo Xuan Dai(Faculty of Physics, Hanoi University of Science), Tran Hoai Thanh(Faculty of Physics, Hanoi University of Science), Cheol-Gi Kim* (Department of Materials Science and Engineering, Chungnam National University)
Abstract
The AlCrN films were grown by RF reactive sputtering method under the selected conditions. The Cr concentration was varied by the number of Cr pieces placed on the Al target. The sample quality has been studied by XRD, Auger spectroscopy, optical absorption and electrical resistant measurements. The XRD and Auger results show that the samples consist of a major phase with the Al1-sCrsN formula, which has a hexagonal structure, and a few percents at. of oxygen, which may form Al2O3. There exist the Cr clusters in the samples with high concentration of Cr. The optical absorption measurement provides the information about the band gap that relates strongly to the quality of samples. The quality of samples is also clearly reflected in electrical measurement, i.e., the temperature dependence of resistance exhibits a semiconductor characteristic only for the samples that have no Cr cluster. In these cases, the values of ionization energies Ea can be derived from R(T) plots by using the function R(T) = Ro exp(Ea/kbT).
Keywords: thin films; diluted magnetic semiconductor; energy band gap
DOI: 10.4283/JMAG.2007.12.4.149
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