Preparation and Characterization of Sol-Gel Derived (Sr,Ba)Bi 2 (Ta,Nb) 2 O 9 Thin Films for Ferroelectric-Gate FET Applications

Abstract

We have fabricated (Sr,Ba) 0.8 Bi 2.2 (Ta,Nb) 2 O 9 (SBBTN) thin films by the sol-gel technique to obtain a small remanent polarization and a large coercive field for ferroelectric-gate FET applications. Ba and Ta compositions are varied from 0 to 0.2 and from 0 to 0.5, respectively. It is demonstrated that the coercive field becomes large by the partial replacement of Ta with Nb atoms and that the Ba doping results in slight decrease of the remanent polarization. A remanent polarization as small as 5 w C/cm 2 and a coercive field as large as 100 kV/cm can be obtained for Sr 0.6 Ba 0.2 Bi 2.2 Ta 1.5 Nb 0.5 O 9 thin films, which were crystallized at 850°C.