Interuniversitair Microelektronica Centrum (imec)

Other

Gerd Norga

Dirk Wouters

Herman E Maes

Dirk Franco

Lucien C Van Poucke

Ria Nouwen

Jan Yperman

Jules Mullens

A ferro-electric capacitor comprising a first electrode comprising at least a layer of a conductive oxide having at least two sub-layers of individual grains, wherein individual grains of a top sub-layer of the two sub-layers are oriented randomly. The capacitor further comprises a second electrode that is isolated from said first electrode. The capacitor further comprises a ferro-electric PZT layer that is sandwiched between said first electrode and said second electrode. A method of making the ferro-electric capacitor is also provided.

Ferro-electric capacitor and method of fabrication of the ferro-electric capacitor

The present invention is related to a method, wherein a PZT layer includes a first PZT sub-layer and a second PZT sub-layer, the Ti-concentration of the first PZT sub-layer being higher than the Ti-concentration of the second PZT sub-layer.

Method of fabrication of a ferro-electric capacitor and method of growing a PZT layer on a substrate

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(Zr,Ti,)O,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.

Method for fabricating ferro-electric thin films using a sol-gel technique

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Antwerp, Belgium

Gerd Norga