Ferroelectric Properties of Chiral Compound $SrBi_2Ta_2O_9$ Thin Films for Non-Volatile Memories

비 휘발성 기억소자 용 $SrBi_2Ta_2O_9$ 박막의 강유전체 특성

  • Lee, Nam-Hee (Div. Metallurgy and Materials Engineering, Chosun University(BK21 team for Development of Intelligent Materials and Its Applications)) ;
  • Lee, Eun-Gu (Div. Metallurgy and Materials Engineering, Chosun University(BK21 team for Development of Intelligent Materials and Its Applications)) ;
  • Lee, Jong-Kook (Div. Metallurgy and Materials Engineering, Chosun University(BK21 team for Development of Intelligent Materials and Its Applications)) ;
  • Jang, Woo-Yang (Div. Metallurgy and Materials Engineering, Chosun University(BK21 team for Development of Intelligent Materials and Its Applications))
  • Published : 2000.06.01

Abstract

Ferroelectric SrBi2Ta2O9 (SBT) thin films of Pt/Ti/SiO2 electrode were fabricated using a sintered SBT target with various Bi2O3 content by rf magnetron sputtering. Good hysteresis loop characteristics were observed in the SBT thin films deposited with 50mol% excess Bi target. SBT thin films crystallized from 650℃ however, good hysteresis loop can be obtained in the film annealed above 700℃. pt/TiO2/SiO2 and Pt/SiO2 electrodes were also used to investigate the Pt electrode dependence of SBT thin films. SBT thin films showed random oriented polycrystalline structure and similar morphology regardless of electrodes with quite different surface morphology. A 0.2㎛ thick SBT film annealed at 750℃ exhibited the remanent polarization (2Pr) of μC/㎠ and coercive voltage(Vc) of 1V at an applied voltage of 5V.

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