Highly reliable ferroelectric memories using BLT thin films and robust integration schemes

Abstract

We report on highly reliable characteristics of 1-Mb ferroelectric memories based on 0.35-μm CMOS technology ensuring ten-year retention and imprint at 175/spl deg/C, which have been successfully developed for the first time. This excellent reliability resulted from newly developed [Bi/sub 1-x/La/sub x/] <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> Ti <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O/sub 12/ (BLT) ferroelectric films with superior reliability performance at high temperatures, and also resulted from robust integration schemes free from ferroelectric degradation due to process impurities such as moisture and hydrogen.