| Autor: |
V.F. Stoliarenko, V.F. Pichugin, Sang Bo Bae, Song Hun Kim, Hong Keun Kim, T.S. Frangulian, Ill Won Kim |
| Rok vydání: |
2002 |
| Předmět: |
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| Zdroj: |
Proceedings KORUS 2000. The 4th Korea-Russia International Symposium On Science and Technology. |
| Popis: |
Ferroelectric bismuth layer oxide SrBi/sub 2/Ta/sub 2/O/sub 9/ (SBT) thin films were prepared on Pt/Ti/SiO/sub 2//Si substrates by pulsed laser deposition technique. The films were deposited at the substrate temperature of 540/spl deg/C and annealed at 800/spl deg/C for 1 hr in oxygen ambient. The composition of mixed powder was Sr/sub 0.8/Bi/sub 2.4/Ta/sub 2.0/O/sub 9/, but the film annealed 800/spl deg/C display Sr/sub 0.7/Bi/sub 2.4/Ta/sub 2.0/O/sub 9/ measured by electron probe micro analyzer (EPMA). The crystalline fluorite phase was maintain in the annealing temperature from 540 to 750/spl deg/C and SBT phase appeared at 750/spl deg/C, crystallized at 800/spl deg/C, which was observed in the X-ray diffraction patterns and scanning electron microscopy images. The grains, which were spherical-like, increased from about 50 to 250 nm in diameter with increasing annealing temperature from 540/spl deg/C to 800/spl deg/C. The SBT film annealed at 800/spl deg/C showed 2P/sub r/=12.6/spl mu/ C/cm/sup 2/, 2E/sub c/=125 kV/cm at applied voltage of 5 V, and the hysteresis loops became saturated at 2 V. The fatigue characteristics of SBT thin films with various applied voltage and frequency have also been investigated. It revealed that the polarization fatigue occurred with decreasing switching voltage and frequency. This significant polarization fatigue was originated due to partial switching when the switching voltage was lower than saturation voltage (/spl sim/3 V). The signal/noise ratio had maximum value of 5 at 3 V, which was capable of low-voltage operation in NVFRAM device. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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