Low-temperature preparation of Sr Bi Ta O ferroelectric thin x 2qy 2 9 film by pulsed laser deposition and its application to metal–ferroelectric–insulator–semiconductor structure

Preferentially 105.-oriented Sr Bi Ta O SBT. thin films on Pt, SiO rn-Si and SiN rSiO rn-Si have been x 2qy 2 9 2 x 2 prepared at low temperature in O2 by pulsed laser deposition. Excess Bi promotes crystallization of the film. The crystalline films have been obtained on Pt and SiO2rSi even at 3508C, which is the lowest process temperature for growing SBT ferroelectric thin films. Metal–ferroelectric–insulator–semiconductor MFIS.structure, which is very important in ferroelectric gate memory FET, has been fabricated by depositing the SBT film on insulator–silicon. The MFIS structures show C–V hysteresis corresponding to ferroelectric hysteresis. Memory windows of the C–V hysteresis are 4.3 V in the SBTr SiO2rSi and 2.5 V in the SBTrSiNxrSiO2rSi. The memory window and fatigue property of the C–V characteristics are improved with decrease of the deposition temperature and the excess Bi content. Little degradations are induced in the C–V characteristics of SiN rSiO rn-Si structure when depositing the SBT film by PLD at low temperature. q2000 Elsevier x 2 Science B.V. All rights reserved.