Characteristics of reactive ion etching of BST thin film

Perovskite (Ba, Sr)TiO₃ (BST) thin film is prepared via Sol-Gel methods. The etching characteristics of Sol-Gel-derived BST films were investigated in a reactive ion etching (RIE) setup using CHF₃/Ar plasma. The morphology and etching rate were measured by X-ray diffraction (XRD) and atomic force microscopy (AFM). The properties of the micropattern after etching were measured by SEM and EDS system. The etching mechanism of BST thin film in RIE was the cooperation of ion bombardment, ions assist chemical reaction and reaction etching effects. The Sr atoms were hard to be removed off than any other atoms. The higher etching rate can be up to 5.1 nm/min.