Young-Hee Joo

Low leakage current in metal-insulator-metal capacitors of structural Al2O3/TiO2/Al2O3 dielectrics

Metal–insulator–metal (MIM) capacitors with Al2O3/TiO2/Al2O3 (ATA) dielectrics were fabricated and investigated. At 0 V and frequencies of 100 kHz and 1 MHz, the MIM capacitors with ATA (3/20/3 nm) and ATA (6/20/6 nm) thin films had low leakage current densities of approximately 5.2 × 10−13 and 1.5 × 10−13 A/cm2, respectively, and high capacitance densities of ∼19.48 and ∼20.13 fF/μm2, respectively. The frequency dispersion effect for these MIM capacitors was very small. The electrical transport mechanism, which is the device conduction mechanism, was determined for the varying structures of MIM capacitors.

The Dry Etching Properties on TiN Thin Film Using an N 2 /BCl 3 /Ar Inductively Coupled Plasma

In this work, we present a study regarding the etching characteristics on titanium nitride (TiN) thin films using an inductively coupled plasma system. The TiN thin film was etched using a /Ar plasma. The studied etching parameters were the gas mixing ratio, the radio frequency (RF) power, the direct current (DC)-bias voltages, and the process pressures. The baseline conditions were as follows: RF power

Dry Etching Characteristics of ZnO Thin Films for the Optoelectronic Device by Using Inductively Coupled Plasma

In this study, we carried out an investigation of the etching characteristics (etch rate, selectivity to ) of ZnO thin films in /Ar inductivity coupled plasma. A maximum etch rate and selectivity of 108.8 nm/min and, 3.21, respectively, was obtained for ZnO thin film at a /Ar gas mixing ratio of 15:16:4 sccm. The plasmas were characterized by optical emission spectroscopy. The x-ray photoelectron spectroscopy analysis showed the efficient destruction of oxide bonds by ion bombardment. An accumulation of low volatile reaction products on the etched surface was also shown. Based on this data, an ion-assisted chemical reaction is proposed as the main etch mechanism for plasmas containing .

Characteristics of Photoresist-derived Carbon Nanofibers for Li-ion Full Cell Electrode

Carbon nanofiber electrode has been fabricated for energy storage systems by the electrospinning of SU-8 precursor and subsequent pyrolysis. Various parameters including the applied voltage, the distance between syringe tip and target collector and the flow rate of the polymer affect the diameter of SU-8 electrospun nanofibers. Shrinkage during pyrolysis decreases the fiber diameter. As the pyrolysis temperature increases, the resistivity decreases dramatically. Low resistivity is one of the important characteristics of the electrodes of an energy storage device. Given the advantages of carbon nanofibers having high external surface area, electrical conductivity, and lithium intercalation ability, SU-8 derived carbon nanofibers were applied to the anode of a full lithium ion cell. In this paper, we studied the physical properties of carbon fiber electrode by scanning transmission microscopy, thermal gravimetric analysis, and four-point probe. The electrochemical characteristics of the electrode were investigated by cyclic voltammogram and electrochemical impedance spectroscopy plots.

The Use of Inductively Coupled CF 4 /Ar Plasma to Improve the Etch Rate of ZrO 2 Thin Films

In this study, we carried out an investigation of the etching characteristics (etch rate, and selectivity to SiO2) of ZrO2 thin films in a CF 4/Ar inductively coupled plasma (ICP) system. The maximum etch rate of 60.8 nm/min for ZrO2 thin films was obtained at a 20 % CF 4/(CF4+Ar) gas mixing ratio. At the same time, the etch rate was measured as a function of the etching parameter, namely ICP chamber pressure. X-ray photoelectron spectroscopy (XPS) analysis showed efficient destruction of the oxide bonds by the ion bombardment, as well as an accumulation of low volatile reaction products on the etched surface. Based on these data, the ion-assisted chemical reaction was proposed as the main etch characteristics for the CF4-containing plasmas.

The Dry Etching Properties of HfAlO3 Thin Films over Si and SiO2 Using Inductively Coupled Plasma Source

In this work, we investigated the etching characteristics of HfAlO3 thin films and the selectivity of HfAlO3 to Si and SiO2 in a CF4/Ar inductively coupled plasma (ICP) system. The maximum etch rates of HfAlO3 thin films was 36.7 nm/min at a gas mixing ratio of CF4/Ar (= 20:80%). At the same time, the etch rate was measured as a function of the etching parameters, such as the RF power, DC-bias voltage and process pressure. The X-ray photoelectron spectroscopy analysis showed the efficient destruction of the oxide bonds by the ion bombardment, as well as the accumulation of low volatile reaction products on the etched surface. Based on these data, the ion-assisted chemical reaction was proposed as the etch mechanism for the CF4-containing plasmas.

Effect of Dry Etching of TiO2 Thin Films Using Inductively Coupled Plasma

In this study, the effect of the dry etching of titanium dioxide (TiO2) thin films was investigated with addition of O2 to BCl3/Ar plasma. The maximum etch rate of TiO2 thin films and the selectivity of TiO2 to SiO2 were 100 nm/min and 1.07 in O2/BCl3/Ar (= 3:4:16 sccm) plasma, respectively. In addition, the etch rate and selectivity were measured as functions of the etching parameters, such as the gas mixing ratio, RF power, DC-bias voltage, and process pressure. The chemical state on the etched surface of TiO2 thin films were investigated by the x-ray photoelectron spectroscopy. To determine the re-deposition and reorganization of residues on the surface, the surface morphology and roughness of TiO2 thin films were examined by the atomic force microscopy.

The Dry Etching Characteristics of TiO 2 Thin Films in N 2 /CF 4 /Ar Plasma

Copyright 2014 KIEEME. All rights reserved. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited. The Dry Etching Characteristics of TiO2 Thin Films in N2/CF4/Ar Plasma

Dry Etching of ITO Thin Films by the Addition of Gases in Cl 2 /BCl 3 Inductivity Coupled Plasma

In this study, we investigated the etching characteristics of ITO thin films and the effects of inert gases added to Cl 2/ BCl3 inductivity coupled plasma. The maximum etch rate of ITO thin film was 130.0 nm/min upon the addition of Ar (6 sccm) to the Cl2/BCl3 (4:16 sccm) plasma, which was higher than that with He or N2 added to the plasma. The ion bombardment by Ar + sputtering was due to the relatively low volatility of the by-products formed in the Cl2/BCl3 (4:16 sccm) plasma. The surface of the etched ITO thin film was characterized by x-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). From the XPS results, it is concluded that the proper addition of Ar and He to the Cl2/BCl3 plasma removes carbon and by-products from the surface of the etched ITO thin film.

Etch Characterization of TiO2 Thin Films Using Metal–Insulator–Metal Capacitor in Adaptively Coupled Plasma

In this work, we investigated the etching characteristics of TiO2, and SiO2 thin films and the selectivity of TiO2 to SiO2 in a CF4/Ar adaptively coupled plasma (ACP) system. The maximum etch rates of TiO2, and for SiO2 thin films were 99 and 255.6 nm/min at a gas mixing ratio of CF4 (75%)/Ar (25%). At the same time, the etch rate was measured as a function of the etching parameters, such as the ACP source power, bias power and process pressure. The X-ray photoelectron spectroscopy analysis showed the efficient destruction of the oxide bonds by the ion bombardment, as well as the accumulation of low volatile reaction products on the etched surface. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the CF4-containing plasmas.