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We report that noise level was reduced by passivating WSe2 field effect transistors (FETs) with high-k dielectric material. Low frequency noise and I-V characteristics of the device were measured from WSe2 FETs before and after the passivation with ZrO2 to confirm the effect of passivation by high-k dielectric material. As a result, there was no significant change in the I–V characteristics. In the low frequency noise analysis, our device showed 1/f noise behaviors, in agreement with the carrier number fluctuation (CNF) model. The passivation process contributed to the reduction of trap sites at the top surface, leading to the decrease of noise level at the low current regime. Extracted volume trap densities were reduced from 2.0 × 1020 cm−3eV−1 to 8.7 × 1019 cm−3eV−1.

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.