Electrical properties and crystallization behavior of Sb x Se100−x thin films
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The structural transformation and transformation kinetics of Sb x Se100−x films (60 ≤ x ≤ 70) were studied to investigate the feasibility of applying Sb x Se100−x alloys in phase-change nonvolatile memories. The temperature-dependent van der Pauw measurements, Hall measurements, X-ray diffraction and a static tester were used to investigate the electrical properties and crystallization behavior of the Sb x Se100−x films. The sheet resistance difference between amorphous and crystalline state was higher than 104 Ω per square According to Hall measurement, Sb x Se100−x films have p-type conduction and the Hall mobility and carrier concentration increases with the increase in Sb content. The crystalline structure of the metastable phase of Sb x Se100−x alloys, which plays a major roll in fast crystallization, is similar to that of Sb2Te (rhombohedral structure). The transition temperature, sheet resistance and activation energy for transformation decrease as the amount of Sb increases in the Sb x Se100−x film. Applying the Kissinger method, the activation energies for crystallization were in the range from 1.90 ± 0.15 to 4.16 ± 0.28 eV. The desired crystallization speed can be obtained by a systematic change of the composition owing to the variation of the activation barrier with stoichiometry.
KeywordsSheet Resistance Phase Change Material Hall Mobility Sb2Se3 Carrier Concentration Increase
The one of the authors, M. J. Kang, would like to thank the Korea Science and Engineering Foundation (KOSEF) for a fellowship to carry out this research work at the I. Physikalisches Institut der RWTH Aachen, Germany.
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