種々の雰囲気下で熱処理した Pt/Ti/SiO_2/Al_2O_3 多層膜の組織と抵抗温度係数 [in Japanese] Structures of Pt/Ti/SiO_2/Al_2O_3 Multilayer Film Annealed in Various Ambients and their Temperature Coefficient of Resistance [in Japanese]
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Microstructures of Pt/Ti thin-films on SiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> substrates and their relationship to the temperature coefficient of resistance (TCR) were investigated by means of X-ray diffraction analysis, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and measurement of electrical resistance. We prepared four different specimens: one as-sputtered and three annealed in vacuum, argon gas and air, respectively. The TCRs were determined to be the largest for the air-annealed specimen and decrease in order of the as-sputtered, the argon-annealed and the vacuum-annealed ones. It is observed that, in the as-sputtered specimen, the Pt film with the preferred (111) orientation deposits on the ultra-thin Ti film with the (00·1) orientation. In the annealed specimens, Ti partly migrates into the Pt film and forms TiO<sub>2</sub> precipitates with the rutile-type structure at the Pt/SiO<sub>2</sub> interface and in the Pt film. The TiO<sub>2</sub> precipitates in the Pt film are relatively small in size, and the amount is observed to be the largest in the air-annealed specimen and decreases in order of the argon-annealed and the vacuum-annealed ones. It is considered that the remaining Ti atoms construct Pt-Ti solid solution in the Pt film, and thereby decrease the TCR from that of the pure Pt film. From these observations, the formation of a large amount of TiO<sub>2</sub> precipitates in the air-annealed specimen results in a substantial decrease of Pt-Ti solid solution, and thereby gives rise to a higher value of TCR. It is clarified from the present investigation that oxgen in air play an important role in the improvement of the TCR value by forming a sufficient amount of TiO<sub>2</sub> precipitates.
- Journal of The Surface Finishing Society of Japan
Journal of The Surface Finishing Society of Japan 53(5), 346-353, 2002-05-01
The Surface Finishing Society of Japan