Inductively coupled plasma etching of hafnium-indium-zinc oxide using chlorine based gas mixtures

Summary form only given. Amorphous Hafnium-Indium-Zinc Oxide(a-HIZO) semiconductor materials are used to replace amorphous Gallium-Indium-Zinc Oxide(a-GIZO) as channel layer of thin film transistors (TFTs) to improve the stability of the electrical characteristics. However, research activities of a-HIZO etching process for the fabrication of TFTs have not been reported. In this work, we present the etching characteristics of HIZO stacked with photoresist using Cl₂/Ar chemistry. Etching behaviours of HIZO have been investigated as a function of source power, bias power and pressure. As the Cl₂ concentration increased from pure Ar, the etch rate of HIZO film was slightly different from the trend of GIZO film. Atomic Force Microscopy(AFM), Depth profile of the HIZO film by Auger Electronspectroscopy(AES) and X-ray Photoelectron Spectroscopy(XPS) of the etched surface was carried to investigate the etching mechanism as Cl₂ increased. Additionally we tried to compare the etching mechanism of HIZO film with GIZO film to confirm the difference of chemical bonds caused by the influence of hafnium doping, estimated that the low chemical reaction between hafnium and Cl₂ based plasma suppress the reactive ion etching.