Journal of Crystal Growth, Vol.262, No.1-4, 327-333, 2004
Ferroelectric Bi3.4Eu0.6Ti3O12 thin films deposited on Si(100) and Pt/Ti/SiO2/Si(100) substrates by a sol-gel process
The bismuth-layered ferroelectric Bi3.4Eu0.6Ti3O12 (BET) thin films have been successfully deposited on Pt/Ti/siO(2)/ Si(1 0 0) and p-type Si(1 0 0) substrates by a sol-gel spin coating process. The 2P(r) and 2E(c) values of the metal-ferroelectric-metal (MFM) type capacitor using BET film annealed at 700degreesC were 38 muC/cm(2) and 309 kV/cm at an electric field of 400 kV/cm, respectively. This 2P(r) value is larger than that of lanthanum-substituted BIT (BLT) thin film and comparable with 2P(r) values of the samarium or niobium-substituted BIT (BST, BNT) thin films. Moreover, the BET film capacitors did not show significant fatigue up to 4.5 x 10(9) switching cycles at a frequency of I MHz. The BET films on p-type Si(1 0 0) substrate (MFS structure) exhibit good capacitance-voltage (C-V) characteristics and memory window of about 2.5 V with sweep voltage of +/- 18 V. Furthermore, frequency dependency of C-V characteristics for the BET film capacitors were measured. The humps and valleys observed in C-V curves were interpreted by introducing charge injection from semiconductor to ferroelectric. (C) 2003 Elsevier B.V. All rights reserved.
Keywords:sol-gel deposition;bismuth titanium oxides;ferroelectric fatigue;field effective transistor