Method for fabricating ferroelectric thin films using a sol-gel technique

摘要

A method is disclosed for the formation of ferro-electric films using a multi coating process based on a sol-gel technique. In particular a method is disclosed to fabricate high-quality thickness scaled PZT films of an alkoxide-type liquid chemical PZT precursor solution, preferably a Pb(ZrxTi1-x)O3 precursor solution, using a sol-gel technique. At least two coated layers are deposited, but the precise number of coated layers depends on the desired thickness of the ferro-electric film. According to the method of the invention, the electrical characteristics of the film as formed are not dependent on the number of coated layers. There are a number of properties, characteristic for the method of the present invention, and resulting in said excellent electrical characteristics. In fact said method can comprise a multi coating process wherein a reduced number of coated layers is used but where intermediate crystallization steps are performed. The ferro-electric films formed using this method have excellent electrical characteristics, provided that a crystallization step is only performed if the thickness of the film formed since the last crystallization step is minimum about 40 to 50 nm. Alternatively, the method can comprise a multi coating process wherein no intermediate crystallization steps are used.